SATA stands for Serial ATA and refers to a method of connecting hard drives to a computer. It is the responsibility of the SATA controller to handle how the hard drives connect to a computer's motherboard. Let's say, for example, that you have three SATA hard drives connected to your motherboard. It is up to the SATA controller to decide on the fastest method of relaying data to and from those hard drives and to make sure that the computer does not become confused when information is coming and going from multiple hard drives at the same time.
RAID stands for Redundent Array of Independent Disks. It is a method through which multiple hard drives are combined in order to create a single usable drive. This gives advantages in performance, redundancy, or both. RAID 1, for example, essentially turns two drives into mirrors of each other so that if one drive fails, data will still be safe on the second. It is the responsibility of the RAID controller to decide how information is read from and written to the two drives and it is also responsible for making the drives work together as if they were a single drive.
SATA is the interface to the HDD - data travels in a serial format as opposed to IDE drive(many wires) that used a parallel interface. Raid is a configuration of multiple HDDs. RAID can be used to speed up data transfer, or to make data secure. There are many RAID modes - try wiki.
EDIT: I see I am not the fastest typist around here;-)