It is a flat circular piece of flexible plastics coated with magnetic oxides.

It is encase in a square plastic or vinyl jacket cover.The jacket give the handling protection to disk surface.

They are also known as diskettes.

Different floppy disk

Types of Floppy Disk There are two types of floppy disk

1 Floppy disk drive.2 31/2-inch Floppy disk.

Floppy disk driveA floppy disk drive is a device used to

read/write data to a floppy disk. It is of interchaeable disk type and allows loading/unloading of different floppy disk as and when they are used.

Speed of floppy disk is about 300 to 400 rpm.And data transfer rate is 10 to 30

kilobytes/second

3½-inch floppy diskIt is the most commanly used floppy disk. It is

consist of 31/2-inch diameter disk encase in a square, hard -plastic jecket cover has a cutout for read /write head to make contact with disk surface. This appear is covered with a sliding metal piece.

All 31/2-inch floppy disk are of double-side type record data on the both surface.

These type of floppy disk come in different capacity.1 Double density2 High density 3 Very high density

Double density 31/2-inch disketteThe duoble density diskettes have 40 trackes

18 sector and 512 bytes/sector giving total storage capacity for the two surface is 720 kb.

High Density 31/2-inch Disketts This diskettes have 80 trackes 18 secters and

512 bytes/sector,diving the total storage capacity is 1.4 mb.

Very High Density 31/2-inch diskettesThis diskettes have 80 tracks, 36 sectors and 512 bytes/sectors, giving the

total disk storage capacity is 2.88 mb.

A hard disk drive (HDD), commonly referred to as a hard drive, hard disk, or fixed disk drive is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Strictly speaking, "drive" refers to a device distinct from its medium, such as a tape drive and its tape, or a floppy disk drive and its floppy disk.

Types of hard disks

PATASATA

PATAPARELLEL ADVANCE TECHNOLOGY

ADVANCEMENTUSES PATA INTERFACE TECHNOLOGYITB USES RIBBON CABLESROTATING SPEED-7200 rpm

SATASerial advance technology advancementUses SATA interface technologyIt uses SATA cablesRotating speed-more than 7200 rpm