RAM 
random access memory 
Microchips located on the computer's motherboard that hold the operating system, applications, and data that are currently being used. When you run an application, such as Microsoft Word, the program is called up from its permanent storage area (such as the hard drive) and copied into RAM, where it sends requests to the CPU. The CPU can access RAM much faster than it can access the hard drive; so the more RAM you have, the more data it can hold, and therefore the less the CPU has to resort to pulling data from storage areas. This type of memory is called random access because data is not stored in chunks in sequential order, but rather is scattered randomly across the chips. Data is held in RAM for only as long as the computer is on; every time you reboot, the operating system is reloaded from the hard drive. Also see DRAM, EDO RAM, SRAM, and virtual memory.