Random Access Memory -- much like your computer's CPU and ROM -- is an essential part of any modern computer system. It is the memory holding bin for all of the work you happen to have on screen, as well as the staging area of an active operating system. RAM allows you to:

• Speed your computer's operation. The more RAM you have, the less your CPU needs to access your hard drive for information. It is much easier and faster for your CPU to get information from your computer's RAM.

• Run multiple applications. Your computer needs RAM to be able to run multiple software applications at the same time. Any files you have open on your desktop also reside in RAM. So the more RAM you have, the more things you can do at once.

Think of the RAM's task as juggling: The more balls you have in the air, the harder you have to work. Without enough RAM, you'll usually get a message telling you there's insufficient memory to open a file or application.

• Operate memory-intensive software. Use of programs like high-end graphics or video-editing software routinely requires your computer to work with enormous files taking up many megabytes of space. Without enough RAM (at least 256 megabytes), these programs will either not work at all, or they'll be so painfully slow that they're unusable.