Simplify the following text for a Grade 4 native English-speaking person.
Original: The physical disks are said to be in a RAID array , which is addressed by the operating system as one single disk . The different schemes or architectures are named by the word RAID followed by a number ( e.g. , RAID 0 , RAID 1 ) .
Simplified: For this reason , all disks used by a RAID 0 should be the same size .