sata=Serial ATA
raid=... just search tech-forums for it, there are a billion post explaining it more thoroughly than i ever could... + i'm too lazy to go dig up an exact explanation, but it basically either fuses (not physically) 2 hdds into one, uses one hdd to exactly backup data, or uses 2 hdds as one and has another 2 back up those 2...
(respectively RAIDs 0,1 and 0+1