Secure Digital (SD) format is used by all major digital memory manufacturing companies of the world including giants like Sony and Siemens. SD cards are available in various memory capacities, sizes and data transfer speeds. The maximum size of the cards is that of SD or SD HC cards and the smaller ones require an adapter that scales them exactly to the size of a standard SD card.While most modern Laptops come with inbuilt SD card readers, devices that have only USB inputs require some kind of reading device to access or modify the data in the cards. SD card readers solve this purpose. SD card can be inserted inside the card slot in the readers which have a USB interface to connect to the desktop.
The Secure Digital (SD) Card or more commonly known as memory cards are small size storage devices that are specially designed to store and transfer data from audio and video consumer electronic devices like digicam, cell phones, voice recorders etc. They are known as secure digital card because they include a copyright protection mechanism that complies with the security of the SDMI (Secure Digital Music Initiative) standards. In this mechanism, a mutual authentication and encryptions are used to protect the card content from illegal usage. The notch in the tip right corner of the card helps to identify the right way of attaching with the device. As per the standards, each SD card is formatted with a File Allocation Table (FAT) file system, which allows every operating system to access the files in that system.