The place where the data, instructions and results received from various sources are stored and stored in the computer is called computer key memory. It is also called memorization or memory in common language. Computer memory is like the human brain. Just as a human keeps all the things in the brain, in the same way, the computer also stores the data in the computer memory and gets it from there when needed.
Data is stored or stored in a computer in a permanent and temporary form. For which he uses different types of memory. There are mainly two types of computer memory.
What is Primary Memory?
Primary memory is a part of the computer itself, so it is also called main memory or internal memory of the computer. This memory is both permanent and temporary. There are two types of primary memory:-
(1). RAM or Random Access Memory
( 2). ROM (ROM) or Read Only Memory (Read Only Memory)
1. RAM:- It is the primary or primary memory of the computer. Its full name is Random Access Memory (Random Access Memory). In this, the work currently being done, instructions and data are stored. The instructions, data or work present in this memory gets deleted or erased when the computer is shut down or when the power goes out. Therefore it is also called Volatile Memory or Temporary Memory.
2. ROM: — This is also the primary or primary memory of the computer. Its full name is Read Only Memory. In this memory the instructions to start the computer are already stored or stored. The instructions and data stored in it can be read only, we can neither delete this data nor can we add new data to it. The instructions, data present in this memory are not deleted or erased even when the computer is shut down or when the power goes out. Therefore it is also called Non-Volatile Memory or Permanent Memory.
What is Secondary Memory (Secondary Memory)?
Secondary memory is not a part of the computer. It is added separately to the computer, hence it is also called external memory. The data stored in it is permanent. It is non-volatile memory, that is, the data stored in it is not deleted when the computer is turned off. According to the need, it can be viewed in future by opening the saved file or data in it. Or you can improve it. And it can also be deleted by the user. Its capacity to store data is higher than that of primary memory. Examples of Secondary Memory (Second Memory) are: — Hard Disk (Hard Disk), CD, DVD, Pen Drive (Pen Drive), Memory Card etc.
Let us now know about some main secondary memory (second memory) :-
1.Hard Disk
We use Hard Disk or HDD to store all the small and big files of our computer. A disk rotates inside the hard disk, the faster the disk rotates, the faster it can store or read data. We measure the speed of rotation of the hard disk in RPM (Revolutions Per Minute). Most of the hard disk is of 5400 RPM or 7200 RPM, obviously the hard disk of 7200 RPM is faster than the 5400 RPM one.
2.Magnetic Tape
Magnetic tape is also a storage device which consists of a thin tape on which magnetic ink is coated. It is used to store analog and digital data. It is like the audio cassette of old times, Magnetic tape is used to store large amount of data. They are cheap Even today it is used to make a backup of the data.
3.Optical Disk
1. CD (Compact Disk):- CD is called compact disc, it is such an optical medium that saves our digital data. About 700 MB of data can be saved in a standard CD. The data in the CD is saved in the form of a dot, in fact the laser sensor installed in the CD drive reads the reflected light from the CD’s dot and creates an image in our device.
2. DVD:- (Digital Versatile Disk)
DVD i.e. Digital Versatile Disc, DVD was followed by CD, although both CD and DVD look the same, but more data can be saved in DVD than CD. Meaning the user can save data from about 4.7 GB to 17 GB in DVD. After the advent of DVD, there was a huge decrease in the demand for CDs in the market.
3.Blu-ray discs
Blu-ray discs are optical discs of new technology, in which the capacity to store data is much higher than CD and DVD. A Blu Ray Disc 50 Gb up to data
