)(n.) An imaginary memory area supported by some operating systems (for example, Windows but not DOS) in conjunction with the hardware. You can think of virtual memory as an alternate set of memory addresses. Programs use these virtual addresses rather than real addresses to store instructions and data. When the program is actually executed, the virtual addresses are converted into real memory addresses.
The purpose of virtual memory is to enlarge the address space, the set of addresses a program can utilize. For example, virtual memory might contain twice as many addresses as main memory. A program using all of virtual memory, therefore, would not be able to fit in main memory all at once. Nevertheless, the computer could execute such a program by copying into main memory those portions of the program needed at any given point during execution.
To facilitate copying virtual memory into real memory, the operating system divides virtual memory into pages, each of which contains a fixed number of addresses. Each page is stored on a disk until it is needed. When the page is needed, the operating system copies it from disk to main memory, translating the virtual addresses into real addresses.
- Check out eWeek's new Research Center, a central and comprehensive library of whitepapers, eBooks, eseminars, webcasts, and more from top industry brands and independent tech journalists »
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »
If hackers get their hands on your company's data, they can wreak havoc on customer relationships and cause tremendous damage to your brand and... Read More »Windows XP: Move Along, There's Nothing to See Here
After more than 12 years of holding the title of most popular operating system in the world, Windows XP is taking center stage for its final... Read More »Report: The Role of Big Data in the Marketing Industry
According to a new study from Infogroup Targeting Solutions, we can expect to see companies spend heavily on big data marketing initiatives in... Read More »
Creating desktop shortcuts to a websites is useful. When you double-click the icon from your desktop it automatically launches the browser and... Read More »Flash Data Storage Vendor Trends
Although it is almost impossible to keep up with the pace of ongoing product releases, here are three recent highlights in the flash data storage... Read More »15 Important Big Data Facts for IT Professionals
Keeping track of big data trends, research and statistics gives IT professionals a solid foundation to plan big data projects. Here are 15... Read More »