Sony VGCRA830 - Manual (Page 93)

RAID array organization
A single hard disk drive has two basic functions — writing and reading data. These functions are handled differently when
using a RAID array.
A RAID array is organized from the physical drives into a physical array. (The hard disk drives are combined into the array.)
These physical arrays are then formatted into a single, logical drive, which communicates with your computer. This
organization enables your computer to use the RAID array as a single hard disk drive.
Page 93