Corporate communica

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MODERN COMMUNICATION

DEVICES

-ELECTRONIC STORAGE DEVICES

Storage Devices are the data storage devices that are used in the computers to store the data.

The memory is of 2 types:-1. Primary memory2. Secondary memory

Primary memory is the volatile memory and secondary memory is the non-volatile memory.

Volatile memory is the kind of memory that is erasable.Non-volatile memory is the kind of memory that cannot be erased.

Secondary memory is used to store the data permanently in the computer. Secondary storage device are usually hard disk drives, floppy disk drives, CD ROM and DVD ROM, USB data card, pendrives,etc.

Other types of storage devices are:-

1. Floppy Disks2. Fixed hard discs3. Portable hard discs4. Magnetic tapes

MAGNETIC DISKMagnetic disk is used for storing large amounts of data.

A recording medium consisting of a thin tape with a coating of a fine magnetic material.

Data is stored in frames across the width of the tape. The frames are grouped into blocks or records which are separated from other blocks by gaps.

Magnetic disk

FLOPPY DISKThis is a removable disk. It is a sequential device. The tape has a beginning and an end, and to move the tape to another song later in the sequence of songs on the tape you have to use the fast forward and rewind buttons to find the start of the song, since the tape heads are stationary. For a long audio cassette tape it can take a minute or two to rewind the whole tape, making it hard to find a song in the middle of the tape.

Floppy disks

Hard diskA hard disk is a large capacity rigid magnetic disk that is used for storing data. Data is read from or

written to hard disk using an arm-like device known as a read/write head. This is a device that is used to write data to the disk (store it on the disk) and to read data from the disk. The access time is the time it takes for the data to be accessed. The faster the access time is the faster the seek time

(time it takes the read/write head to get to a specific position on the disk).

Hard disk

OPTICAL DISKThis is a type of media used for storing data. It reads

data using laser beam. There are two common types of optical disks : CD and DVD. Both types use the same method to read the data. A low-powered laser uses a

lens to focus the laser beam on a part of the disk. Under the plastic layer on the reflective side there are areas that reflect light differently. The drive can detect these differences and converts theses differences into

ones and zeroes that can be interpreted by the computer.

Optical disk

PEN DRIVESA USB flash drive, also known under a variety of other names,is a data storage device that includes flash memory with an integrated Universal Serial Bus (USB) interface. USB flash drives are typically removable and rewritable, and physically much smaller than an optical disc. USB flash drives are often used for the same purposes for which floppy disks or CDs were used, i.e., for storage, data back-up and transfer of computer files. They are smaller, faster, have thousands of times more capacity, and are more durable and reliable because they have no moving parts.

Pen drives

Thank you -M.Dimple

2nd B.COM ‘b’