How to distinguish or identify switching power supply and linear power supply? Find a professional answer!

I am a switching power supply and module power supply, but I can't guarantee that the answer I give you is accurate and authoritative, because switching power supply is an independent professional discipline, and its classification, principle and application can't be simply explained. Firstly, the definition of switching power supply is analyzed: due to the rapid development of industrial electronics, power frequency electricity can no longer meet various voltage requirements, so how to convert the power frequency grid voltage into our practical voltage requires the use of a voltage conversion device, which is called a power converter. The basic definition of switching power supply is to control the normal energy conversion of power converter through switching transistors. Linear power supply is the earliest form of power converter, which is composed of a transistor working in linear region and a load in series. The advantage of this circuit is that EMI interference is very small and there are few devices. The disadvantage is that the efficiency is extremely low and the transistor is very hot. Nowadays, high-frequency switching power supply uses magnetic materials to convert energy, which has many advantages such as high efficiency, small size, high frequency and low cost, and has been widely used in IT power supply, medical care, industrial electronics and other industries. If you are interested in this field, I suggest you read some books, and you will get a lot of Principles and Applications of Switching Power Supply by 1 Zhang Zhansong and Magnetic Components in Switching Power Supply by Zhao Xiuke. I hope the above answers are helpful to you.