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
To figure out if your hard drive is sata or ide, find out what type of cable it uses to hook up to your motherboard. ide uses a ribon cable, while sata uses a smaller cable.
as for raid, its different ways to use hard drives, you could combine your hard drives ( you usualy use two hard drives the same size) or have redundant drives for failsafe.
