Webopedia on Google+Webopedia on TwitterWebopedia on FacebookTech Bytes Blog
Main » TERM » M »

main memory

Refers to physical memory that is internal to the computer. The word main is used to distinguish it from external mass storage devices such as disk drives. Another term for main memory is RAM.

The computer can manipulate only data that is in main memory. Therefore, every program you execute and every file you access must be copied from a storage device into main memory. The amount of main memory on a computer is crucial because it determines how many programs can be executed at one time and how much data can be readily available to a program.

Because computers often have too little main memory to hold all the data they need, computer engineers invented a technique called swapping, in which portions of data are copied into main memory as they are needed. Swapping occurs when there is no room in memory for needed data. When one portion of data is copied into memory, an equal-sized portion is copied (swapped) out to make room.

Now, most PCs come with a minimum of 32 megabytes of main memory. You can usually increase the amount of memory by inserting extra memory in the form of chips.

 







TECH RESOURCES FROM OUR PARTNERS
LATEST ARTICLES
Slideshow: History of Microsoft Operating Systems

Microsoft Windows is a family of operating systems for personal computers. In this article we look at the history of Microsoft operating... Read More »

Slideshow: Interesting Facts About Google Search

From Goats to Penguins, a server outage and trillions of searches, our slideshow presents interesting facts about Google and the Google.com... Read More »

Slideshow: 5 Apps to Make Your Commute a Breeze

We've scoured the App and Play Stores to bring you five of the most useful apps to have with you on the road, plus a bonus in-car feature. Read More »

STUDY GUIDES
Java Basics, Part 1

Java is a high-level programming language. This guide describes the basics of Java, providing an overview of syntax, variables, data types and... Read More »

Java Basics, Part 2

This second Study Guide describes the basics of Java, providing an overview of operators, modifiers and control Structures. Read More »

The 7 Layers of the OSI Model

The Open System Interconnection (OSI) model defines a networking framework to implement protocols in seven layers. Use this handy guide to compare... Read More »