External storage


In computing, external storage comprises devices that store information outside a computer. Such devices may be permanently attached to the computer, may be removable or may use removable media.

Types of external storage

Magnetic storage

Optical storage devices have media that use laser light technology for data storage and retrieval.

Compact disc

Types of Compact Discs include:
stands for Digital Versatile Disc. Its speed is much faster than CD but not as fast as hard disk. The standard DVD-5 technology has a storage capacity of 4.7 GB per layer; most DVDs have a single layer but up to four layers are specified. Also DVD storage capacity changes with recording format.

Blu-ray

storage capacity is up to 50 gigabytes of data.
The Blu-ray Disc is a digital optical disc format. It was originally created to take the place of the DVD format due to its expanded storage capacity. The name "Blu-ray" is derived from the use of a blue laser that is used to read the disc. This would be in contrast to the red laser used to read DVD Discs.

M-DISC

s are available as DVD or Blu-ray discs.

Flash memory devices

Memory card

Memory cards are flash memory storage media used to store digital information in many electronics products. The types of memory cards include CompactFlash, PCMCIA, secure digital card, multimedia card, memory stick etc.

Memory stick

Sony introduced memory stick standard in 1998. Memory stick is an integrated circuit designed to serve as a storage and transfer medium for digital data. It can store data in various form as text, graphics, digital images etc. transfer of data is possible between devices having memory stick slots. Memory sticks are available in various storage sizes ranging from 4 MB to 64 MB. The dimensions of a memory stick are 50 mm long, 21.5 mm wide and 2.8 mm thick. The transfer speed of memory stick is 160 Mbit/s.

USB drives

A USB flash drive, also variously known as a, thumb drive, pen drive, jump drive, disk key, disk on key, flash-drive, memory stick or USB memory, is a data storage device that includes flash memory with an integrated USB interface