RAID 0 isn't strictly RAID at all but striping - the data is spread between two or more drives theoretically combining the capacity of each. RAID 1 is mirroring where identical copies of your data are stored on each drive. You only get the capacity of an individual drive but the data is still accessible even if a drive breaks down.Be careful of any guidance you receive based about performance. Traditionally RAID is implemented with intelligent controllers that are basically special-purpose computers in their own right and are capable of blistering levels of performance. This is the set up that is assumed by most studies examining RAID. However, firmware based RAID, typically included on even basic modern motherboards, is becoming increasingly prevalent. Those are dependent on the host computer to coordinate all disk activity and as a result performance is usually little better than a single drive.