A storage device is a device designed to store in formation in it. Storage devices work on the different principles using electronic, magnetic and laser technology.
PRIMARY MEMORY
It is based on electronics and consists of integrated circuits. It is a random access memory and its short name isRAM. It vanishes when the computer is switched off.
SECONDARY STORAGE DEVICE
The data storage devices are the secondary memory of the computer. It is used to store the data permanently in the computer. When we open the program data is moved from secondary storage into primary storage. The secondary storage devices are audio-video cassettes and hard disk.
This is based on laser technology. It is plastic disk on which data stored in the form of microscopic reflecting and non-reflecting spots which are called pits and lands. Pits are the spiral tracks encoded on the top surface of CD. A fine laser beam scans the surface of rotating disk to read data. Pits and lands reflect different amount of laser light falling on the surface of CD.
To use this device we use CD ROM, DVD ROM, COMBO’s and many other ROMs. A CD can store over 680 megabytes of computer data.
