RAM - Random Access Memory. It's the memory that you have in your computer. RAID - Redundant Array of Inexpensive Disks. An array of physical disks, usually treated by the operating system as one single disk, and often forced to appear that way by the hardware. The reason for using RAID is often simply to achieve a high data transfer rate, but it may also be to get adequate disk capacity or high reliability.
Redundancy means that the system is capable of continued operation even if a disk fails.
There are various types of RAID array and several different approaches to implementing them. Download Written by Stas Bekman .