Random Access Memory(RAM):

This is where data can be temporarily stored and also retrieved.  RAM is volatile which means that when the power is removed, all contents are lost.  RAM is measured in Megabytes (MB) and Gigabytes (GB). There are various types of RAM and you have to consult the manual for your motherboard as to why type you will need.  The types include: SRAM, DRAM, DDR2, DDR3 to name a few of the more commonly used.

If you are running Windows XP operating system, 1GB of RAM would be fairly suffice.  If you are running Windows Vista you should not get less than 2GB because it is a resource hog.

Also the programs you run on your computer will determine the amount of RAM you may need.  For standard uses such as word processing software, surfing the Internet, and standard application software, you would only need 1GB at the most.  For those more advanced multimedia capabilities, spreadsheet programs, music, gaming online, etc. 1GB to 4GB of RAM would be useful.  Those that create professional web sites or use graphic intensive programs need at least 4GB of RAM.