Partitioning separates the drive into logical drives (C:, D:, 
  E:, etc. in MS Windows). Every drive has at least one primary partition (C:) 
  and may have several extended partitions. The primary partition contains drive 
  booting information in the MBR (Master Boot Record) and keeps a record of all 
  other partitions. [4,18]
   
Gregg Williams, 294805, CS_134 Web Report