External and Internal Storage Devices: Optical, Magnetic & Semiconductor Storage

Storage in computer hardware is typically about holding information that are inputted by the user, permanently or temporarily. Now the storage device are mainly of two types either internal or external storage. Internal is basically inside the computer such as hard disk this is the most basic level in the computer system need to hold operating system so that it can access input and output devices. It allow to store data and application to load into the memory and ready for use. Data in the internal memory accessed faster than data stored on the external storage. But having one disadvantage if hard disk is failed because of the any reason all the data is lost and cannot be recover. Now we talk about external this is separate from computer and connected to computer via suitable interface and data passes back and forth across the interface. Main advantage of using such devices that they are portable and can be used and provide safe backup with internally stored data. Disadvantages of using these devices are take extra space around the computer. Examples of external storage devices are: portable hard disk, magnetic tape, DVDs and CDs, memory cards and so on.

Optical Storage

Optical Storage is a device for storage method in which data is written and readable with a laser and purpose is to store backup. Data written methods such as CDs and DVDs. From some of the years Optical storage is replacement for drives in personal computers and tape backup in mass storage. This is durable and protected to environmental conditions. Now the optical speeds approaching hard drives as said by OSTA(Optical Storage Technology Association). There are some of the new formats introduced Blu-ray and UDO i.e. ultra density optical and also use blue laser to increase capacity.

Magnetic Storage

Magnetic Storage is the most common and enduring form of removable storage device which is used in mostly systems. It is used as a drive which is mechanical device connects to computer in that you can insert the media that actually used as a storage device. The media used in removable storage device is made up of iron oxide and that oxide is ferromagnetic material, here the meaning of the term ferromagnetic is if you expose it into magnetic field it is permanently magnetised that is known as a disk or cartridge. The drive use motor to rotate the device at a very high speed and access information stored by the heads. There are many types of magnetic storage devices hard drives, Tapes, Floppy disk, Iomega.

Semiconductor Storage

This storage device is used to store digital information that is fabricated by using integrated circuit technology also known as semiconductor technology which is an essential parts of today world. As there is rapid improvement in the requirement of such kind of technologies there are some of the related technologies emerged are ROM, RAM, EPROM, EEPROM, Flash Memory, DRAM and so on. Now we are going to discuss Flash memory its function and features. In this data can written and erased on the individual cell basis. To re-programme different areas of chip at different levels electronic equipment are used. It is non-volatile which make it useful to use. Used in many different fields like mobile phone, memory cards for digital cameras and many other applications.