RAID 0 

RAID 0 really isn't RAID, because there's no redundancy at all.
RAID 0 stripes data across two (or more) drives to maximize read and write performance.
The different drives split up the read or write portions of the data in order to improve throughput. Two identical drives, for example 300GB each,are combined to look like a single 600GB drive, but if one drive fails,we lose all your data from both drives. RAID 0 requires at least two drives.

RAID 1 

RAID 1 is purely redundant drives. In the last example, a pair of 300GB drives would look like a single 300GB drive. The data is mirrored on both drives. Write performance is a little slower, because we're duplicating every disk write across two separate drives. Read performance can actually be a little faster, because the reads can be split up so that one drive reads one part of a file, while the other drive reads another part. RAID 1 requires two drives.

RAID 5

RAID 5 needs three drives at a minimum. The data is striped across the drive, as with RAID 0, but additional parity data is also striped across the drive. This parity stripe contains check-sum information on the data written. If a single drive fails, the data on the failed drive can be reconstructed from the parity stripe. A RAID 5 device can survive the failure of one drive at a time, as long as time is taken to rebuild the data fully from the failed drive with a replacement. RAID 5 read and write performance is much faster than RAID 1, but a little slower than RAID 0. Three 300GB drives would appear as 600GB (300GB is used for the parity stripe).

RAID 10

RAID 10 takes a set of RAID 1 volumes and stripes those for increased performance. But you need a minimum of four drives. Using our hypothetical 300GB hard drive, four 300GB drives would look like one 600GB drive.
What RAID's type to use depends on our needs. Each type of RAID shows positive sides and negatives too. Generally the most used is RAID5m because is a right way between expensive and functional solution.