In 1946, developed by the University of Pennsylvania, the world's first program-controlled computer is known as the Electronic Numerical Integrator And Calculator (Electronic Numerical Integrator And Calculator), referred to as the ENIAC. the computer's Word length of 12 bits, the main memory is only 17K, computing speed of 5,000 times per second addition, *** the use of 18,800 tubes, 1,500 relays, covers an area of 150m2, weighing 30t, power consumption of 150kw, the cost of more than one million U.S. dollars. Today it seems that this computer is both expensive and heavy, low computing speed, word length is not long enough, and more power consumption. But it is today's different sizes and patterns of various types of electronic computers pioneer, laid the foundation for the development of computer technology. If the ENIAC is called the first generation of electronic computers, it has developed into the fourth generation.
The first generation (1946-1958) tube digital computer
Computer logic components using tubes, the main memory using magnetic drums, magnetic cores, external memory has begun to use tape software is mainly prepared in machine language, and the gradual development of assembly language. Mainly used for scientific computing.
The second generation (1958-1964) transistor digital computer
The computer's logic elements using transistors, the main memory using magnetic cores, external memory has begun to use disk; software has begun to have a great deal of development, the emergence of a variety of high-level languages and compiled programs. At this time, the computer speed significantly increased, power consumption decreased, life expectancy increased. Computers have been developed for a variety of transaction processing, and began to be used for industrial control.
Third generation (1964-1971) integrated circuit computers
The logical components of the computer using small and medium-sized integrated circuits, the so-called SSI and MSI; software development is faster, there has been a time-sharing operating system, the scope of application is increasingly expanding.
The fourth generation (after 1971) of large-scale and ultra-large-scale integrated circuit computers
The logic element of the computer using large-scale integrated circuits (LSI), in a single piece of silicon can be integrated into the integrated circuits of 1,000 to 20,000 transistors. Ultra-large-scale integrated circuits currently integrate up to 50 million transistors.
Currently the rapid development of computer technology, the main direction of development of a large, giant development, the second is to small, miniaturized development.
1. large, giant computer
In order to adapt to the needs of modern science and technology development, the requirements of the computer to increase the speed of operation, increase the capacity of the main storage, the emergence of large and giant computers. Such as the U.S. Cray company produced Cray-1, Cray-2, Cray-3 giant computer is more famous. China's Galaxy I is l0 billion times per second parallel giant computer. Giant computer symbolizes a country's scientific and technological strength, only a few countries have the ability to produce. Mainframe speed, large capacity, to solve the past can not calculate the real-time and complex mathematical problems, but the equipment is huge, expensive.
2. Small, micro-computers
Small, micro-computers, the emergence, popularization and application of small, to adapt to aerospace, missile technology and general applications of small size, low cost, high reliability requirements.
Microcomputer (Microcomputer) heart - the central processing unit (CPU) integrated in a small chip, known as the microprocessor MPU (Micro processing Unit), in order to differentiate between large, medium and small computers, CPU. In addition to the MPU, there are large-scale integrated circuits made of main memory and input/output interface circuits, which are linked by a bus structure. If coupled with the appropriate peripherals such as monitors (CRT), keyboards and printers, this becomes a microcomputer system (Microcomputer System). At present, the microcomputer function has been very strong, for example, "Pentium 4" (Pentium) CPU integration has reached more than 40 million transistors, the clock frequency up to 3,000 MHz. due to the structure of a simple, general-purpose, inexpensive, micro-computer has become the field of modern computers an extremely important branch, the development of a rapid progress. branch of the modern computer field, the development of the rapid progress.
Two, the use of computers
We are now in the age of science and technology, computer applications everywhere. From everyday life to sensitive high-tech contact, this chapter can help you understand the application of computers in different areas.
3.1 Education
Computers as Learning ToolsComputer-assisted learning is the use of computers as learning tools. There are many computer-aided learning programs that help students learn different subjects with the help of text, images, sound, video and animation. You can also test what you have learned and get the results of the test immediately.
There is also a wealth of learning resources available on the Internet, and students can learn something outside of the classroom on their own.
Computers as Teaching ToolsComputers are also great teaching aids. Through the use of computers, teachers are able to make learning more interesting by presenting content more clearly, explaining difficult concepts, and demonstrating difficult experiments with more interesting multimedia (images, video, animation, sound, and text) effects.
Computers as a tool for school administrationSchool administration can be made more efficient with the help of computers. Schools can use computers to store and process large amounts of data, such as each student's personal records, class lists, test scores for various subjects, library book data, etc.
This is the first time that a computer has been used in a school.
3.2 Entertainment
Computer GamesComputer games can be categorized into adventure games, action games, educational games, intellectual games, simulation games, strategy games, etc. Most of them contain a large number of visual and sound effects, and a good computer game can trigger the imagination of the participants in the game and provide them with the fun of challenge and the joy of success.
Movie and TV productionWith computers, we can create special sound and visual effects for movies or TV programs; nowadays, many sci-fi or action movies are produced with the help of computer technology, bringing us new forms of entertainment.
Interactive TV
Today, all we need to do is connect a control box and we can enjoy video-on-demand at home. All you have to do is select the movie you want to watch, and the computer system will send the video over the phone line for you to watch on your TV at home.
3.3 Home Appliances
Home AppliancesVideo cassette recorders, washing machines, refrigerators, air conditioners, automatic temperature control, microwave ovens, many of the heating program, many of which are controlled by the computer.
Smart HomeThe so-called smart home, is through programming, voice control or telephone control, the whole house electrical appliances are handed over to the computer control, switch on and off on time.
3.4 Transportation
Traffic monitoringTraffic lights, electronic road pricing, and air, land, and sea traffic monitoring systems are all controlled by computers.
DispatchRailway systems, dispatches between cars, ships, and airplanes are all computerized.
TicketingTicketing systems such as vending machines, Octopus, etc. are all computerized.
3.5 Communication
TelephoneTelephone systems in most countries have been computerized, further improving the sound quality, wiring, and working environment of telephone buildings.
E-mailE-mail software allows people to send and receive messages over a computer network. It is a fast, economical and convenient method of messaging.
Real-time communicationOnline games, chat rooms, ICQ, Internet telephony, video conferencing, and so on. And video conferencing allows people to make face-to-face calls with other people through the computer network.
3.6 Business
FinanceFinancial institutions rely on computers for the operation and record keeping of their branches. You can use ATMs to make deposits, withdrawals, or transfers, and now you can connect to a bank's computer system using a telephone, TV, or computer to
1. check your account balance;
2. p>
3. obtain financial information.
SalesDepartment stores and supermarkets use computerized point-of-sale terminals to read data (names and prices) of goods, print invoices, and control inventory, and the system and connects each point-of-sale terminal to control inventory levels and order quantities.
ServicesMany service industries have begun to utilize computers to improve efficiency, hotels can use computers and the Internet to book rooms, restaurants use computers to place orders and checkout, travel agencies use computers to book flights and hotels for their customers, shopping companies use the Internet to make purchases, etc.
3.
3.7 Office Applications
Office automation is the use of computerized equipment to handle office work. The following types of applications are commonly used in a general automated office:
Document processing softwareDocument processing software can be used to create, edit, proofread, format, and print documents.
SpreadsheetsSpreadsheet software can perform calculations, analyze data, and present data.
DatabasesDatabase software stores, organizes, and updates large amounts of information.
Presentation SoftwarePresentation software can be used to display reports or present data to attendees in a meeting.
Three, the computer has the following characteristics:
fast computing power, sufficiently high computational accuracy, strong memory
Four, the basic components of a computer system
operator
central processor controller
mainframe computer internal memory
hardware external memory
peripheral devices Inputs Devices
Microcomputer Output Devices
Systems Operating Systems
System Software Service Software
Software Compilation or Interpretation Systems
Information Management Software
Applications Auxiliary Design Software
Word Processing Software
Graphic Software
Various Program Packages
V. Composition of the hardware system and the main function of each component
Computer hardware system consists of operators, controllers, memory, input devices and output devices and other five major components
1. The operation and processing of data is carried out in the operator. Here the "operation", not only is the addition, subtraction, multiplication, division and other basic arithmetic operations, but also includes a number of basic logical operations.
2. Controller
Controller is the command center of the entire computer, it takes out the control information in the program, after analysis, it will be required to send out the operation and control signals, so that all parts of the coordinated work.
3. Memory
The place where programs and data are stored and provided on command Memory is the part of the computer that is used by the relevant parts.
1) The main technical parameters of memory: storage capacity, access speed and bit price (i.e. the price of a binary bit).
2)Memory capacity: indicates the computer's ability to store information, and to byte (byte) as a unit. 1 byte for 8 binary bits (bit). Because the capacity of the memory is generally large, especially the capacity of the external memory to improve very quickly, and therefore to 210 (1024) as a multiple of the name of the unit is constantly expanding. The relationship between these units is as follows: (kilo, megabyte, gigabyte), and therefore the unit name is continuously expanded by multiples of 210 (1024). The relationship between these units is as follows: (thousand
1byte = 8bit lKB = l024byte
lMB = 1024KB lGB = 1024MB
3) the composition of the memory system:
Memory system includes the main memory (internal memory), auxiliary memory (external memory) and cache memory (cache). (cache). The three according to the access speed, storage capacity, the advantages and disadvantages of the price of the bit composed of hierarchical structure, in order to improve the CPU's increasingly high speed requirements, and a better solution to the contradictions of the three technical parameters. The hierarchy of exchanging data between them is shown in Figure-2.
4) Main memory
Stores the program, data and intermediate information currently involved in the operation. It exchanges information with the operator and controller.
Features: small storage capacity, fast access speed, appropriate bit price. Stored information can not be retained for a long time (power failure is lost
4. Input devices.
The most common keyboard and mouse, we can use the keyboard ｛Figure 1 ｝ input and mouse ｛Figure 2 ｝ operation to transfer some basic information to the computer, as well as the computer's hard disk and floppy disk, will be stored in advance in the disk of information through the operation of the computer; in addition to the scanner ｛Figure 3 ｝, digital cameras ｛Figure 4 ｝, digital camcorders ｛Figure 5 ｝ and so on, can be some of the photos and videos taken. In addition, there are scanners, digital cameras, digital cameras, digital camcorders, etc., which can transfer photos and videos to the computer. The earwig in our computers can also be used as an input device, which can be used in conjunction with the software in the computer to transfer sound to the computer. The input device also has an electronic touch screen, which can be used at the post office to check the postal codes of different parts of the country.
5. Output Device
It is a part of human-computer interaction for data output. It is the result of various calculations data or information in the form of numbers, characters, images, sound and other forms of expression. Commonly, there are monitors ｛Figure 7｝, printers ｛Figure 8｝, plotters, image output system, voice output system, magnetic recording equipment
VI, the basic concept of data storage
Data storage is a data stream in the process of processing the temporary files generated or the processing of information that need to be found. Data is recorded in some format on the computer's internal or external storage media. Data stores are to be named, and this naming is to reflect the meaning of the components that characterize the information. Data flow reflects the data flowing in the system, showing the characteristics of dynamic data; data storage reflects the data at rest in the system, showing the characteristics of static data.
Commonly used storage media are disks and tapes. Data storage organization varies by storage medium. In the tape data only according to the sequential file access; in the disk can be used according to the requirements of the use of sequential access or direct access. The data storage method is closely related to the data file organization, the key is to establish the logical and physical order of the record correspondence between the determination of the storage address, in order to improve the speed of data access.
(Continued below)
VII, software basics
Operating system" (Operating System, referred to as OS) is one of the most important system software, mainly used to manage computer hardware resources, and provide us with control and operation of the computer's environment.Windows98 is a typical operating system software. Windows 98 is a typical operating system software, we are through the desktop, menu, control panel and other parts to operate and control our computer.
Common operating systems include DOS, Windows 3.x, UNIX, Mac OS, etc.
The operating system is the supreme commander of the computer system, all the software depends on the operating system instructions. Both hardware and software are inseparable from the operating system support. In general, the operating system is burdened with the following aspects of the important mission:
Manage the computer system's various hardware resources, such as CPU, memory space, disk space, input/output devices. 2 Manage various] software resources in the computer system. Responsible for coordinating the relationship between the various hardware of the computer system, between software, between hardware and software, and rationally organizing the workflow of the computer. As a bridge to exchange information between the computer and the user. When the computer is configured with an operating system, people no longer directly operate the computer hardware, but the use of the operating system to provide commands and services to deal with a variety of computer hardware and software. It can be said that the operating system establishes the interface and channel between the user and the computer.In short, leaving the management and intermediary role of the operating system, the computer for ordinary people is of no value. DOS, OS/2, UNIX, Windows, Mac OS, etc. can be applied to the microcomputer on the operating system, of which DOS and Windows are the most commonly used microcomputer operating system.
The relationship between people, computers and operating systems is described in the book.
Application software is a variety of applications prepared for some practical application or to solve some problem. These programs are highly practical and can be dedicated to solving a specific problem in an application area. Such as transaction management software, word processing software, auxiliary teaching software, auxiliary design software, a variety of game software and so on.
In addition, application software must be dependent on a certain operating system. That is, an application software can usually only run in one operating system.
Software use ethics: use legal software, use genuine software; do not illegally copy software, do not use pirated software.
3. Computer viruses and their prevention and control
Computer viruses are not the usual sense of the kind of biological or bacterial viruses, it is also a computer program.
Computer viruses are infectious, proliferative, insidious, and destructive. See the book for a detailed description and examples.
Preventive measures for computer viruses are:
Do not use floppy disks and CD-ROMs of unknown origin that cannot be identified as having a virus. If you must use foreign floppy disks, you should first use antivirus software to check for viruses and make sure that they do not carry viruses before using them. The company does not illegally copy software or use pirated software. The system disk, program disk, and floppy disk with important data are write-protected and backed up.Regular use of antivirus software for computer antivirus testing, in order to detect and remove viruses in a timely manner.
Computer virus removal commonly used antivirus software: KILL, KV300, Rising Star antivirus software, Norton and so on.
The most thorough way to clear a virus is to repartition and format the disk that has been infected with the virus. Formatting the disk will delete all programs and data on the disk, including the operating system, and thus the virus as a program will be removed. However, since the consequences of formatting a hard disk are more serious and it is difficult to install an operating system after formatting, you should not format a hard disk easily and hire a professional to do it.
VIII, numerical value in the computer in the form of
Numerical value in the computer in the form of machine number, the computer can only recognize 0 and 1, the use of binary, and in everyday life people use decimal, "as Aristotle pointed out long ago, today's widespread adoption of the decimal system, only the vast majority of us are born with 10 fingers of the anatomical facts. The result of anatomical facts.
There are positive and negative values, and computers use the highest bit of a number to hold the sign (0 is positive, 1 is negative). This is the original code of the machine number. Assuming that the machine can handle the number of bits for 8, that is, the word length of 1byte, the original code can represent the value of the range of
(-127 ~ -0 +0 ~ 127)***256.
With a numeric representation, it is possible to perform arithmetic operations on numbers. However, it was soon discovered that the multiplication and division operations were correct when using the original code with signed bits, but the addition and subtraction operations were problematic, as follows: Suppose the word length is 8bits
( 1 ) 10- ( 1 )10 = ( 1 )10 + ( -1 )10 = ( 0 )10
To perform the original code operation: (00000001)original + (10000001)original = (10000010)original = ( -2 ) is clearly incorrect.
Since there is no problem in the addition of two positive numbers, it was realized that the problem is with the negative numbers with sign bit.
The inverse of each bit except the sign bit produces an inverse code (for positive numbers, the inverse is the same as the original code). The inverse code has the same space as the original code and corresponds to it one by one. Here is the subtraction operation of inverse:
( 1 )10 - ( 1 ) 10= ( 1 ) 10+ ( -1 ) 10= ( 0 )10
To do the inverse operation: (00000001) inverse + (11111110)inverse = (11111111)inverse = ( -0 ) There is a problem.
( 1 )10 - ( 2 )10 = ( 1 )10 + ( -2 )10 = ( -1 )10
To do the inverse operation: (00000001) inverse + (11111110)inverse = (11111110)inverse = ( -1 ) is correct
The problem arises in the (+0) and (-0), and there is no distinction between positive and negative zeros in people's concepts of computing. In people's conception of computing, there is no difference between positive and negative zero. (The Indians were the first to use zero as a marker and put it into arithmetic, and Indian mathematics and decimal counting, which included zero, contributed greatly to human civilization).
The concept of complement was introduced. The complement of a negative number is the addition of one to the inverse of the number, while a positive number remains unchanged, and the inverse of a positive number is the same as the complement. In the complement, (-128) is used instead of (-0), so the range of the complement is:
(-128~0~127)***256.
Note: (-128) doesn't have a corresponding original or inverse, (-128) = (10000000) The addition and subtraction of the complement is as follows:
( 1 ) 10- ( 1 ) 10= ( 1 )10 + ( -1 )10 = ( 0 )10
(00000001)-supplement + (11111111)-supplement = ( 00000000)-supplement = ( 0 )10
(00000001)-supplement + (11111111)-supplement = ( 0)10
(00000001)-supplement + (11111111)-supplement = ( 00000000)complement = ( 0 ) correct
( 1 ) 10- ( 2) 10= ( 1 )10 + ( -2 )10 = ( -1 )10
(00000001)complement + (11111110)complement = (11111111)complement = ( -1 ) correct
So the complement is designed to:
(1) enable the the sign bit can participate in the operation together with the RMS part, thus simplifying the rules of arithmetic.
(2) To convert subtraction operations to addition operations, further simplifying the line design of the operators in the computer
All these conversions are carried out at the lowest level of the computer, and the original code is used in other high-level languages such as assembly and C that we use. After reading all these above you should have a new understanding of primitive, inverse and complementary codes!
Nine, commonly used external devices
Keyboard, mouse, monitor, printer, audio, headphones, scanner
Ten, what is the CPU
CPU is the English "Central Processing Unit/central processing unit" abbreviation. CPU is generally composed of logical computing unit, control unit and storage unit. In the logic operation and control unit includes some registers, these registers are used for the CPU in the processing of data in the process of temporary preservation of data, in fact, we buy the CPU, do not need to know its structure, as long as you know its performance can be. CPU's main performance indicators are: the main frequency that is the clock frequency of the CPU (CPU Clock Speed). This is what we care about the most, what we say 233, 300, etc. refers to it, generally speaking, the higher the main frequency, the faster the CPU speed, the higher the whole machine. Clock frequency that is, the CPU's external clock frequency, provided by the computer motherboard, before the general is 66MHz, there are motherboards support 75 83MHz, Intel's latest chipset BX to use 100MHz clock frequency. In addition, VIA's MVP3, MVP4 and other non-Intel chipsets have also begun to support the 100MHz external frequency. Elite's BX motherboards can even support 133MHz, which is preferred by overclockers. Internal Cache (L1 Cache): The cache closed inside the CPU chip is used to temporarily store part of the instructions and data during CPU operation, and the access speed is the same as the main frequency of the CPU, and the capacity unit of the L1 cache is generally KB. The larger the L1 cache is, the fewer times the data is exchanged between the CPU and the L2 cache and memory with slower access speeds, so that the relative computing speed can be increased. The faster the computation speed of the computer can be increased. External cache (L2 Cache): CPU external cache, Pentium Pro processor L2 and CPU running at the same frequency, but the cost is expensive, so the Pentium II running at the equivalent of half the frequency of the CPU, the capacity of 512 K. In order to reduce the cost of Inter produced a CPU without L2 named Celeron, performance is also good, is ideal for overclocking. The performance is also good and ideal for overclocking. MMX technology stands for "Multimedia Extended Instruction Set", a new technology adopted by Intel in 1996 to enhance the Pentium CPUs for audio-visual, graphics, and communications applications. By adding 57 MMX instructions to the CPU, in addition to the MMX instructions in the instruction set, the L1 cache in the CPU chip was increased from 16KB to 32KB (16K means life + 16K data), therefore, the MMX CPU is able to increase its ability to handle multimedia by 60% compared to the ordinary CPU when running programs containing MMX instructions. Currently, all CPUs are equipped with MMX technology, except for the P55C and Pentium II CPUs, as well as the K6, K6 3D, MII, and so on. Manufacturing process: the current CPU manufacturing process is 0.35 micron, the latest PII can reach 0.28 micron, in the future the CPU manufacturing process can reach 0.18 micron.
XI, the concept of memory
In the composition of the computer structure, there is a very important part of the memory. Memory is used to store the program and data components, for the computer, with memory, memory function to ensure normal operation. There are many types of memory, according to its use can be divided into the main memory and auxiliary memory, the main memory is also known as internal memory (referred to as memory, RTHK called memory).
Memory is where the program and the data are stored, for example, when we use WPS to process the manuscript, when you type in the characters on the keyboard, it is stored in memory, and when you choose to save the disk, the data in the memory will be stored on the hard (magnetic) disk. Before understanding it further, it is also important to recognize its physical concepts.
Memory generally uses semiconductor storage units, including random memory (RAM), read-only memory (ROM), and cache (CACHE).
● Read Only Memory (ROM)
ROM stands for Read Only Memory, and when ROM is manufactured, information (data or programs) is deposited and stored permanently. This information can only be read out, and generally cannot be written, even if the machine is powered down, this data will not be lost.ROM is generally used to store the basic programs and data of the computer, such as the BIOS ROM.Its physical form is generally a double-row in-line (DIP) integrated block.
● Random Memory (RAM)
Random Access Memory (Random Access Memory) indicates that data can be read from it as well as written to it. The data stored in it is lost when the machine is powered off. The memory sticks that we usually buy or upgrade are used as the memory of the computer. A memory stick (SIMM) is a small piece of circuit board that holds the RAM blocks together, and it is inserted into the memory slots in the computer to reduce the amount of space taken up by the RAM blocks. The common memory sticks on the market today are 1G/strip, 2G/strip, 4G/strip, and so on.
● Cache memory (Cache)
Cache is also a concept we often encounter, that is, usually see the first level of cache (L1 Cache), the second level of cache (L2 Cache), the third level of cache (L3 Cache) these data, it is located in the CPU and memory between the memory is a read and write faster than the memory of the memory. When the CPU writes or reads data into memory, this data is also stored into the cache memory. When the CPU needs this data again, the CPU reads the data from the cache instead of accessing the slower memory, and of course, if the needed data is not available in the Cache, the CPU will go back to read the data in memory.
● Physical memory and address space
Physical memory and storage address space are two different concepts. But because they are very closely related, and both use B, KB, MB, GB to measure their capacity, it is easy to create confusion in understanding. Beginners to clarify these two different concepts, help to further understand the memory and use the memory.
Physical memory refers to the actual existence of specific memory chips. For example, the memory stick and the ROM chip loaded with the system BIOS on the motherboard, the display RAM chip and the ROM chip loaded with the display BIOS on the graphics card, as well as the RAM chip and the ROM chip on the various adapters are all physical memories.
The memory address space is the range over which the memory is encoded (coded addresses). Encoding is the assignment of a number to each physical memory unit (a byte), often called "addressing". The purpose of assigning a number to a memory unit is to make it easy to find it, read and write data, which is called "addressing" (so, some people also refer to the address space as the addressing space).
The size of the address space and the size of the physical memory are not necessarily equal. An example to illustrate this problem: a floor *** there are 17 rooms, which are numbered 801 to 817. These 17 rooms are physical, and their address space is encoded in three bits, which ranges from 800 to 899 *** 100 addresses, so it is clear that the address space is larger than the number of actual rooms.
For microcomputers above the 386 level, the address bus is 32-bit, so the address space can be up to 2 to the 32nd power, i.e., 4GB. (However, our common 32-bit operating system windows xp can only recognize or use up to 3.25G of memory, even though 64-bit vista is able to recognize up to 4G of memory, but it can only use up to 3.25G.) 3.25G of RAM.)
Well, it can now be explained why different memory types such as: regular memory, reserved memory, upper memory, high end memory, expanded memory and extended memory are created.
XII, the concept of microprocessor
Microprocessor (MPU), to put it bluntly, is a miniaturized CPU. that is, the use of ultra-large-scale integrated circuit technology to do the CPU into one or several chips.
Thirteen, computer security knowledge
What is malware?
Answer: Malware is a collective term for software that disrupts the normal operation of the system, generally speaking, there are the following manifestations:
Forced installation, can not be uninstalled
Installation of the homepage after modification and locking
Installation of the ads pop-up at any time after the automatic pop-up
Self-replicating code, similar to viruses, slowing down the system
What is a plugin?
Answer: Plug-ins are programs that automatically execute with the start of Internet Explorer, and according to where plug-ins are loaded in the browser, they can be categorized as Toolbar, Browser Helper (BHO), URL SEARCHHOOK, and ActiveX (ACTIVEX) downloads.
While some plug-ins help make it easier for users to browse the Internet or invoke Internet accessibility features, others are known as adware or spyware. These malicious plug-ins monitor the user's online behavior and report the recorded data to the creator of the plug-in for the purpose of placing advertisements, stealing game or bank account passwords, and other illegal purposes.
Because plug-in programs are distributed by different publishers with varying levels of technical expertise, plug-in programs are likely to conflict with other running programs, resulting in a variety of page faults, runtime errors, and other phenomena that can block normal browsing.
What is a Trojan horse?
A: Trojan horse, called "Trojan horse" in English, takes its name from the Greek myth of Trojan horse. It is a hacking tool based on remote control, with the characteristics of covert and unauthorized. The so-called covert refers to the Trojan horse designer in order to prevent the Trojan horse is found, will use a variety of means to hide the Trojan horse, so that even if the server found infected with the Trojan horse, due to the inability to determine its specific location, often can only look at the "horse" sigh. The so-called non-authorized refers to once the console and server connection, the console will enjoy most of the server's operating privileges, including modification of the file, modify the registry, control the mouse, keyboard and so on, and these powers are not the server to give, but through the Trojan horse program to steal.
What are the hazards of Trojan:
1. sending QQ and msn tails to trick more people into visiting malicious websites and downloading Trojans
2. stealing users' accounts, and achieving the purpose of illegally obtaining virtual property and transferring online funds through stolen accounts and passwords
3. monitoring users' behaviors and obtaining important user information
How to prevent Trojans?
1. Develop good online habits, do not visit the bad small sites.
2. Try to download software from large download sites or official software websites.
3. Install antivirus software, firewalls, and regular virus and Trojan scans.