Storage devices are used to store data and programs permanently. These devices are used to store large volume of data and program. Storage devices are also called backing storage devices, secondary storage devices, or auxiliary storage devices. Two important instructions or information from storage medium to memory. Writing is a process of coping the data, instructions or information from memory to a storage medium.
Types of Storage Devices
Different types of storage devices are as follows:
1. Magnetic Tape
Magnetic tape is a flexible plastic tape coated with magnetic material. It is widely used when large amount of data is to be processed sequentially. An advantage of magnetic tape is that it is very cheap and economical storage medium. Its major disadvantage is that it is very slow and it is only sequential.
2. Magnetic Disk
Types of Magnetic Disk
Different types of magnetic disks are as follows:
a. Floppy disk or Diskette
Floppy disk is also called diskette. It consists of a thin plastic disk coated with magnetic material. This disk is enclosed in a plastic jacket. It can store a small amount of data. Data access speed of floppy disk is slower than hard disk. It is inexpensive storage media. The standard size of floppy disk is 3 1/2 inch and its capacity is 1.44MB. The circular piece of plastic on 3 1/2 inch disk is enclosed in a shell. A piece of metal covers the reading and writing area. It is called shutter. When the disk is inserted into a disk drive, the shutter opens to read the stored data with floppy disk drive. The read / write head in floppy disk drive is used to read and write data on floppy disk.
b. Hard Disk
Hard disk is a type of magnetic disk. It is also called fixed disk because it is fixed in the system unit. A hard disk consists of several circular disks called platters sealed inside a container. The container contains a motor to rotate the disk. It also contains an access arm and read/write head to read and write data to the disk. The platters are used to store data. A platter in a hard disk is from 320GB and more. It is much faster than floppy disks. The data stored on hard dis is safer than floppy disk.
c. Zip Disk
Zip disk is a portable disk. It has more storage capacity than floppy disk. Its storage capacity is up to 1000 MB. Zip disk can be read / written by using Zip drive. It is used for taking the backup of large data.
Optical Disk
Optical disk uses laser technology to read and write data. The LASER stands for light Amplification through Stimulated Emission of Radiation. Laser beam writes on the surface by creating small pits (hole) in the disk.Optical drive reads data by focusing laser beam on the surface of the disk.A laser detects the presence of a pit.The presence of pit indicates 1and absence of pit indicates 0. Laser beam converts these pits into digital data.Optical disk storage capacity is from 600 MB to over 1 GB
Solid State Storage Devices
The solid state storage devices or flash memory devices are unique among all storage devices.Some solid state storage devices are non volatile and some are volatile.These devices are portable and provide fast access to data.They use very little power.They are very useful to store data on mobile devices and transport data from once device to another.They are widely used in digital camera, MP3 music players, notebook computers and cell phones.
Types of Solid State Storage Device
Different types of solid - state storage are as follows:
1.USB F Lash DRIVE
USB flash drive is also knows as pen drive or key chain drive. It provides much greater storage capacity than floppy disk or Zip disk.A flash drive can store 64 GB or more data.It can be plugged into any USB port. It is small and lightweight storage device. USB flash drive requires no card reader .The size of USB flash drive is similar to the size of highlighter.It is durable and can be carried on a key ring.
2.Flash Memory Cards.
Flash memory cards are widely used in PDA, digital camera, cell phones and notebook computers. Generally, these card are not interchangeable.
1. Magnetic Tape
Magnetic tape is a flexible plastic tape coated with magnetic material. It is widely used when large amount of data is to be processed sequentially. An advantage of magnetic tape is that it is very cheap and economical storage medium. Its major disadvantage is that it is very slow and it is only sequential.
2. Magnetic Disk
Magnetic disk is the most widely used storage media. A magnetic disk is a thin, circular metal plate / platter coated with magnetic material. Information can be recorded on or read from the magnetic surface. A disk must be formatted before it can be used. The formatting process prepares the disk so that it can store data. Formatting process creates tracks and sectors on disk. Each track on a disk is divided into sectors. Each sector holds a specific number of characters. A sector is the smallest physical storage unit on a disk. Its size is normally 512 bytes. The magnetic disk is a random access storage media. It means that any part of the disk is directly accessible.
Types of Magnetic Disk
Different types of magnetic disks are as follows:
a. Floppy disk or Diskette
Floppy disk is also called diskette. It consists of a thin plastic disk coated with magnetic material. This disk is enclosed in a plastic jacket. It can store a small amount of data. Data access speed of floppy disk is slower than hard disk. It is inexpensive storage media. The standard size of floppy disk is 3 1/2 inch and its capacity is 1.44MB. The circular piece of plastic on 3 1/2 inch disk is enclosed in a shell. A piece of metal covers the reading and writing area. It is called shutter. When the disk is inserted into a disk drive, the shutter opens to read the stored data with floppy disk drive. The read / write head in floppy disk drive is used to read and write data on floppy disk.
b. Hard DiskHard disk is a type of magnetic disk. It is also called fixed disk because it is fixed in the system unit. A hard disk consists of several circular disks called platters sealed inside a container. The container contains a motor to rotate the disk. It also contains an access arm and read/write head to read and write data to the disk. The platters are used to store data. A platter in a hard disk is from 320GB and more. It is much faster than floppy disks. The data stored on hard dis is safer than floppy disk.
c. Zip Disk
Zip disk is a portable disk. It has more storage capacity than floppy disk. Its storage capacity is up to 1000 MB. Zip disk can be read / written by using Zip drive. It is used for taking the backup of large data.
Optical DiskOptical disk uses laser technology to read and write data. The LASER stands for light Amplification through Stimulated Emission of Radiation. Laser beam writes on the surface by creating small pits (hole) in the disk.Optical drive reads data by focusing laser beam on the surface of the disk.A laser detects the presence of a pit.The presence of pit indicates 1and absence of pit indicates 0. Laser beam converts these pits into digital data.Optical disk storage capacity is from 600 MB to over 1 GB
Categories of Optical Laser Disks:
Different categories of laser disks are as follows:
- CD-ROM:
- CD-R
- CD-RW
- Digital Video Disk (DVD)
Solid State Storage Devices
The solid state storage devices or flash memory devices are unique among all storage devices.Some solid state storage devices are non volatile and some are volatile.These devices are portable and provide fast access to data.They use very little power.They are very useful to store data on mobile devices and transport data from once device to another.They are widely used in digital camera, MP3 music players, notebook computers and cell phones.
Types of Solid State Storage Device
Different types of solid - state storage are as follows:
1.USB F Lash DRIVE
USB flash drive is also knows as pen drive or key chain drive. It provides much greater storage capacity than floppy disk or Zip disk.A flash drive can store 64 GB or more data.It can be plugged into any USB port. It is small and lightweight storage device. USB flash drive requires no card reader .The size of USB flash drive is similar to the size of highlighter.It is durable and can be carried on a key ring.
2.Flash Memory Cards.
Flash memory cards are widely used in PDA, digital camera, cell phones and notebook computers. Generally, these card are not interchangeable.