relevant knowledge

Memory card, also known as SD card, is an independent storage medium used in digital products such as mobile phones, digital cameras, portable computers and MP3 players. Generally, they are in the form of cards, so they are collectively referred to as "memory cards", also known as "digital memory cards", "digital memory cards" and "memory cards".

Secure digital card is referred to as SD card for short. Literally, this card is a security card, which is better than CF card and early SM card in security performance. It is a brand-new memory card product jointly developed by Panasonic, Toshiba and Sandisk. Its biggest feature is to ensure the security and confidentiality of data through encryption function. SD card can be regarded as an upgrade of MMC in many ways. Both of them have the same appearance and working mode, but the thickness of MMC card is slightly thinner, but all machines using SD card devices can use MMC card. Its overall dimension is 32 mm× 24 mm× 2.1mm.