Computer Memory

There are mainly two categories of memory device inside the computer.

1. Primary Memory :- a) RAM b) ROM

2. Secondary Memory :- a) Hard disk b) Optical disk c) Floppy disk d) Pendrive

Primary Memory :- Primary memory is the internal memory within the computer that stores data, instructions & meaningful results temporarily. It is also two categories:-

a) RAM :- Ram stands for Random Access Memory. It is read/write memory. It is an area in the computer system that temporarily holds user data & programs. It contents are lost when the power supply is switched off. That's why, it is said to be volatile memory.

b) ROM :- ROM stands for read only memory. It holds a store of programs which tells the computer how to work. The contents of ROM are not loss when you switched off the computer. ROM is the considered as non-volatile memory. The user only can read this type of memory. These all are set into the computer's memory during the time of manufacture by the company.

Secondary storage device :-

a) Hard disk :- It is the main storage main device. It consists of all of the computer's item as well as documents created by using all software. It lies inside the board (CUP box) . Hard disk is a device used for storing large quantity of data. It consists of one or more platters. Each platter is a thin, circular metal plate coated on both sides with a magnetic material. Data can be read from & written onto the disk with the help of read/write heads. Today's computers typically come with a hard disk that contains several billion bytes (giga bytes) of storage space.

b) Floppy disk :- A floppy disk is a small data storage device which is generally used for transfer data from the hard disk. It is a circular piece of thin plastic material with magnetic coating on one or both sides. It is sealed with a protective jacket. A floppy is inserted into a floppy drive to read data from it or write information on it. Floppy disks come in different sizes. The most common size available today is 3.5 inches which holds upto 1.44 MB (mega byte) of data.

c) Optical disk :- Optical disks are produced using laser technology and as a result offer much higher density & reliability than magnetic disks. Optical disk is a glass or plastic disk coated with reflecting medium. It is portable & can hold large amount of data. Data is read & recorded through a laser beam. The optical disks have the capacity to store a large amount of data in the form of text, graphics, audio & video. CD-Rom (compact disk read only memory) & DVD (digital Versatile disk) are the common types of optical disks.

d) Pendrive :- Pendrive is a small, lightweight removable disk. It consists of a small printed circuit board. It is very small in size & can be carried in a pocket or hand like a pen. It has a high storage capacity & can transfer data at a very high speed. It is also called thumb drives.