Computer Memory and Basic Units of Measurement

Hey learner,

In this post we're going to discuss about computer memory which acts as one of the most important elements in a computer system. No doubt without memory any task can't perform in mannered way. Everywhere memory is needed to store some rules and regulation upon which task performed. In this way, memory in computer system are of many types. Let's explore it.

Computer Memory

Memory play a vital role in any system. The computer memory is one of the most important elements in a computer system. It may be internal or external storage area. It holds the data and instructions during processing in the form of binary numbers.

Types of Computer Memory

It can be classified into two types Primary memory and Secondary memory.

1. Primary Memory

This is known as main memory. It is internal memory used by computer to hold data and instructions. This memory has limited storage capacity. Primary memory holds the data and programs needed at that instant by CPU. Primary memory is volatile in nature i.e. it requires constant power supply to motion the current information.

Types of Primary Memory

There are two types of primary memory i.e. RAM and ROM.

(i) RAM:- It stands for Random Access Memory. It is the internal memory that can be read from as well as written to. This memory is volatile. It can hold data only on temporary basis.In this memory If current is interrupted, data is lost.

Types of RAM

The two main forms of RAM are as follows:

• Static RAM:- It is also written as SRAM.
• Dynamic RAM:- It is also written as DRAM.

(ii) ROM:- Read Only Memory, in such memory information once stored remain fixed, i.e. it can not be changed. So, ROM can only be read and ROM used.

Types of ROM

ROM is further sub-divided into three types: 

• PROM (Programmable Read Only Memory)
• EPROM (Erasable Programmable Read Only Memory)
• EEPROM (Electrically Erasable Programmable Read Only Memory)

Cache Memory

It is a storage buffer that stores the data that is used more often, temporarily and makes them available to CPU at a fast rate. The data and instructions that are required during the processing of data are brought from the secondary storage devices and stored in the RAM. Benefits of Cache Memory:- It increases the speed of processing. It is smaller in size. Generally, computers have cache memory of sized 256KB to 2MB.

Secondary Memory

Secondary memory, also known as Secondary Storage or Auxiliary Memory. It is a permanent storage device. CPU does not access the secondary memory directly. The content in it must first be copied into the RAM to be processed. Secondary memory is non-volatile in nature.

Magnetic Disks	Optical Discs	Solid State
Floppy Disk	CD	Pen/Flash Drive
Hard Disk Drive	DVD
Magnetic Tape	Blu-ray Disc	row3 col 3

Basic Units of Measurement

When user uses a RAM, ROM, Floppy disk or Hard disk, the data is measured in some types units. In computer terminology, many units are used to measure and they are called Nibble, Bit, Byte, Kilobyte, Gigabyte etc.

Units of Computer Memory Measurements

• Bit (Binary Digit) Smallest unit of data (i.e. either 0 or 1)
• Nibble A group of 4 bits or half a byte.
• Byte A group of 8 bits. It represent 256 (2⁸) disctince values.
• Kilobyte (KB) It is actually 2¹⁰ bytes or 1 KB-1024 bytes.
• Megabyte (MB) it is actually 2²⁰ bytes or 1 MB 1024 KB.
• Gigabyte (GB) It is actually 2³⁰ bytes or 1 GB 1024 MB.
• Terabyte (TB) It is actually 2⁴⁰ bytes or 1 TB1024 GB.
• Petabyte (PB) It is actually 2⁵⁰ bytes or 1 PB = 1024 TB.
• Exabyte (EB) It is actually 2⁶⁰ bytes or 1 EB = 1024 PB.
• Zettabyte (ZB) It is actually 2⁷⁰ bytes or 1 ZB = 1024 EB.
• Yottabyte (YB) It is actually 2⁸⁰ bytes or 1 YB = 1024 ZB.
• Brontobyte It is actually 2⁹⁰ bytes or 1 Brontobyte = 1024 YB.
• Geopbyte It is actually 2¹⁰⁰ bytes or 1 Geopbyte = 1024 Brontobyte. Geopbyte is the highest unit of memory measurement.