The RAM, or Random Access Memory, is where the operating system, application programs, and data in current use are kept on the computer. Though it reads faster than any other storage device, the data stays only as long as the computer is running. All the data is loaded into RAM, usually from the hard disk, once the computer is switched on. As soon as the computer is switched off, the RAM loses its data.

The RAM also has a much smaller memory than a hard disk. It has "discrete" or separate microchip modules plugged into the holes of a computer's motherboard. These holes are connected through what is known as a bus or a set of electrical paths to the processor.

The RAM never runs out of memory, it just keeps going. But when it gets full, the processor has to continuously go back to the hard disk to overlay the old data in RAM with the new thus slowing down the computer. The time taken to do this is expressed in nanoseconds. RAM size is important because the more RAM you have, the fewer times does it have to read data from the hard drive.

Today's PCs offer a RAM of 16 or more megabytes. For graphic applications, a RAM of 32, 64, or even 128 megabytes are used. RAM increases in multiples of 8 megabytes. PCs are usually designed to allow users to insert additional RAM modules within certain limits. New technologies promise to offer even more RAM. Check out the nonvolatile RAM that retains data when the computer is turned off or if there is a power failure. A battery within the computer powers it, and what's more it can write its contents to and restore them from an EEPROM. A RAM without its disadvantages? That's life today!