What is memory?, primary(semiconductor) memory, secondary memory and storage devices?
Answers
Answer: Memory is very much like our brain as it is used to store data and instructions. Computer memory is the storage space where data is to be processed, and instructions needed for processing are stored. The memory is divided into a large number of smaller portions called the cell. Every cell/ location has a unique address and a size.
Two types of memories are:
Primary Memory
Secondary Memory
In this tutorial, you will learn
What is Memory?
What is Primary Memory?
RAM (Random Access Memory)
ROM (Read Only Memory)
What is Secondary Memory?
Types of Secondary memory
Characteristic of Primary Memory
Characteristic Secondary Memory
Primary Memory Vs Secondary Memory
What is Primary Memory?
Primary memory is the main memory of the computer system. Accessing data from primary memory is faster because it is an internal memory of the computer. The primary memory is most volatile which means data in primary memory does not exist if it is not saved when a power failure occurs.
The primary memory is a semiconductor memory. It is costlier compared with secondary memory. The capacity of primary memory is very much limited and is always smaller compares to secondary memory.
Two types of Primary Memory are:
RAM
ROM
RAM (Random Access Memory)
Random access memory which is also known as RAM is generally known as a main memory of the computer system. It is called temporary memory or cache memory. The information stored in this type of memory is lost when the power supply to the PC or laptop is switched off.
ROM (Read Only Memory)
It stands for Read Only Memory. ROM is a permanent type of memory. Its content is not lost when the power supply is switched off. The computer manufacturer decides the information of ROM, and it is permanently stored at the time of manufacturing which can not be overwritten by the user.
What is Secondary Memory?
All secondary storage devices which are capable of storing high volume data is referred to secondary memory. It's slower than primary memory. However, it can save a substantial amount of data, in the range of gigabytes to terabytes. This memory is also called backup storage or mass storage media.
Types of Secondary memory
Mass storage devices:
The magnetic disk provides cheap storage and is used for both small and large computer systems.
Two types of magnetic disks are:
Floppy disks
Hard disks
Flash/SSD
Solid State Drive provides a persistent flash memory. It's very fast compared to Hard Drives. Frequently found in Mobile phones, its rapidly being adopted in PC/Laptop/Mac.
Optical drives:
This secondary storage device is from which data is read and written with the help of lasers. Optical disks can hold data up to 185TB.
Examples
CD
DVD
Blue Ray
USB drives:
It is one of the most popular types of secondary storage device available in the market. USB drives are removable, rewritable and are physically very small. The capacity of USB drives is also increasing significantly as today 1TB pen drive is also available in the market.
Magnetic tape:
It is a serial access storage device which allows us to store a very high volume of data. Usually used for backups.
Characteristic of Primary Memory
The computer can't run without primary memory
It is known as the main memory.
You can lose data in case power is switched off
It is also known as volatile memory
It is a working memory of the computer.
Primary memory is faster compares to secondary memory.
Explanation: