RAID 1 offers redundancy through mirroring, i.e., data is written identically to two drives. RAID 0 offers no redundancy and instead uses striping, i.e., data is split across all the drives. This means RAID 0 offers no fault tolerance; if any of the constituent drives fails, the RAID unit fails.
Called "mirroring," RAID 1 does not increase performance. However, if one drive fails, the second drive is used, and the failed drive is manually replaced. After replacement, the RAID controller duplicates the contents of the working drive onto the new one.
While RAID 1 uses two drives, RAID 10 involves at least four drives and combines the mirroring of RAID 1 with the striping of RAID 0. RAID 1 vs. RAID 5 comes down to what's more important in terms of performance and cost. A RAID 1 drive pair can handle twice the amount of reads of a standalone disk drive.