Alternatively referred to as a media card reader, a card reader is a hardware device that lets you read and write data on a memory card such as a multimedia card. Some card readers only have one card slot, and some have multiple card slots for different cards and media. In the picture below, is an example of a USB media card reader from Kingston. As can be seen in the example picture, this card reader has a slot for miniSD, microSD, SD/MMC, MMCmicro, CF/MD, M2, and MS/DUO cards.
Memory card readers are also built into some printers, laptops, and can be put in a 5 1/4" or 3 1/2" drive bay in desktop computers. The picture to the right shows a 3 1/2" drive bay media card reader for a desktop computer.