What are sd card and micro sd card?

Answer 1

Size - is the main difference. A 'standard memory card is approximately 25mm square. A micro SD card is about a third of the size. There are adaptors available so you can use a micro SD card in a standard SD card slot.

Answer 2

Secure Digital (SD) is a non-volatile memory card format developed by the SD Card Association (SDA) for use in portable devices. Micro SD is a physically smaller version.