the main diffrences are the speed, also you can put SATA drives into arrays and hence either provide failsafe security or double your HDD speed and size (just to examples of many array types)
RAID 1:
Mirror, Whatever goes on one drive goes on the other at the same time, therefore if one drive fails you havent lost anything you just unplug the faulty drive run up the second drive and theres every thing o/s data anything that was on the other drive.
RAID 0:
Stripe, Two drives that your o/s will only see as one the two drives are added together, whenever you save something to disc it gets split in two, half goes on one disc and the other half goes on the other disc, hence halfing the write/read time, also you get twice the storage space i.e. two 250Gb drives in RADI 0 = 500Gb drive thats twice as fast. downside is that if one drive fails you've lost everything on both drives.
In both cases the drives have to be idetical drives.
Also most mobo's/SATA controllers are hot swapable so you dont have to turn your machine of to change your hdd, good for backups.
I've also seen some companies trying to push e-SATA (external SATA) as a standard, providing faster data transfer.