Memory and Virtual Memory Management

What is Memory Management?

One of the main functions of Operating systems is Memory Management. Memory Management may be defined as the process of managing the optimal use of main memory that is RAM (Random Access Memory). RAM is much faster than hard disk. So RAM is used to store data and instructions temporarily while they are being executed by CPU ( Central Processing Unit or PROCESSOR ). CPU can get data and instructions from RAM much faster that from hard disk.

As we know CPU is a very very fast device. It may execute billions of instructions per second. CPU will have to wait for data and instruction from hard disk because getting data from hard disk is very slow. That is why RAM is used. So data and instructions needed for execution are brought into main memory that is RAM first. Now RAM provides data and instructions to CPU rapidly.

What is Memory Management and virtual memory management

Operating System allocates the required memory are in main memory to programs that are a candidate for execution. The allocated memory area will be de-allocated when the program will finish execution.

What is Virtual Memory?

Some times, main memory that is RAM is not enough to run larger programs. In this case, some operating systems apply the technique of VIRTUAL MEMORY to overcome the problem of small RAM.

The operating system uses a particular area of hard disk as additional RAM (virtually). The most wanted part of the program in execution may be kept in RAM while the remaining part of that program may on the particular part of the hard disk. This is called Virtual Memory. The area of hard disk used for virtual memory is called a SWAP file. The Swap file is used to exchange data and instructions of a running program between RAM and Hard disk.

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Explain different types of storage devices

Topic: Explain different types of storage devices in Computer systems Storage Devices Storage devices are used to store data and instructions permanently. Storage devices are also called secondary storage devices / backing storage devices / external storage devices or auxiliary storage devices. Examples of storage devices include Hard Disk, CD and DVD etc. Why Secondary Storage Devices are Used? Secondary storage devices are used because: Primary memory(RAM) is volatile and temporary. When computer is switched off, all data in ram is erased. Storage devices can store large amounts of data and instructions permanently whereas Primary memory has less capacity of storing data. Types Of Storage Devices There are three main types of storage devices: Magnetic Tape Magnetic Disk Optical Disk Flash Memory storage devices 1. Magnetic Tape Magnetic tape is the oldest storage device. It is made of plastic coated with m...

Explain Different Types Of Output Devices

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What are Different Types of Input Devices With Examples

Topic: Different types of input devices of a computer system with examples, pictures and explanation: Topics Covered are: Definition of Input Devices Functions of Input Devices ( How input devices work? ) Examples of Input Devices Pictures / Images of different input devices Different Examples of Input Devices With Description Keybboard Mouse Trach Ball Trackpad Joy Stick Light Pen Microphone Scanner Graphic Tablet ( Digitizer ) Digital Camera Touch Screen ( I/O Device / Dual Device - Perform Both Functions input + Output ) INPUT DEVICES ( Definition ) Input devices are used to enter data and instructions into computer memory from external world. Input Device is a hardware part of the computer that is used to enter data and instructions into computer memory. The examples of input devices include: Keyboard, Mouse , Track ball, Track Pad, Joy stick, Touch Screen, Light pen, Scanner , Digital Camera, Microphone, Graphics tablet e...

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