Hard Drives

Read-Write Head

Is used for reading and writing data to and from the data disks of the same to its designated function read-write head (English "head").
From this operation is comparable to a record needle, but with one significant difference:
The head is not on the plate, but floats in microscopically small distance from it. Hence the property that it can change dramatically different than a record needle's position, without destroying the disc. This circumstance is to thank also that the data need not be written in a spiral but are arranged in concentric circles.

course located at the end of the needle head no, but a tiny electromagnet, which are written on the surface of the disc data by magnetizing zeros or ones.
The reading process works on the same principle, only in reverse: from the magnetic coating of the interpretation of the reading head, whether it is a zero or one.

Since the supported distance between disk and head by the rotation of the data disks must be parked in the read-write head before turning into an area where the plate is insensitive to the placement of the head.