A memory card reader is a computer hardware device that reads and writes data to and from a media source, such as the memory card that holds pictures from a digital camera, according to Computer Hope. A six-in-one reader reads and writes six different types of media formats.
Computer Hope explains that a memory card reader transfers all types of data to and from a computer, including music, e-books, movies, computer games and pictures. A six-in-one media card reader provides the flexibility of reading six different sizes and types of media, or memory cards, using only one device. Typical media card formats, as of June 2014, include Compact Flash, Secure Digital, MultiMedia Card and microSD.
There are two different types of memory card readers. The first type is portable and plugs in to the USB port on a laptop or other device on one side with the other side available for the media cards. The second type is built in to a laptop or desktop computer. A built-in memory card reader typically has more than one opening to accommodate the different types of media cards.