SD card is an independent storage medium used in digital products such as mobile phones, digital cameras, portable computers and MP3 players. Generally in the form of cards, they are collectively referred to as "memory cards", also known as "digital memory cards", "digital memory cards" and "memory cards". The memory card is small in size, convenient to carry and simple to use. At the same time, because most memory cards have good compatibility, it is convenient to exchange data between different digital products. In recent years, with the continuous development of digital products, the storage capacity of memory cards has been continuously improved, and their applications have been rapidly popularized.