Hard drive
From Free Knowledge Base- The DUCK Project: information for everyone
A high-capacity, self-contained storage device containing a read-write mechanism plus one or more hard disks, inside a sealed unit.
A magnetic disk on which you can store computer data.
A single hard disk usually consists of several platters. Each platter requires two read/write heads, one for each side. All the read/write heads are attached to a single access arm so that they cannot move independently. Each platter has the same number of tracks, and a track location that cuts across all platters is called a cylinder.