A memory module has several memory chips. The computer uses this memory constantly to temporarily store information, (or data), while it is working with it. If a computer has a lot of memory, it can store more temporary information and operate faster. People with good memories also "store" more information and do things faster, because they don't waste a lot of time trying to remember things. Memory modules come in several different sizes. Each is able to hold different amounts of data. Everything stored on a memory module is erased as soon as the computer is turned off. Hard drives and removable disks are used to store information that needs to be saved permanently.