Computing terms explained in plain English
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Energy transmitted as waves. Light, radio waves and Wifi signals are all forms of radiation.
A type of button where only one choice can be made at any time.
A system for storing data efficiently and automatically backing up computer hard disks, but it can be more trouble than it's worth.
Random-access memory. The computer's working area, used for data storage while the PC is switched on. Its capacity is measured in megabytes (MB): the more memory your PC has, the more things it can process simultaneously and the faster it will seem. Any information in Ram will be lost when the power is switched off.
A design of memory claimed to offer very high performance, albeit at a high price. Developed by Rambus and licensed to Ram manufacturers, it is found in Pentium III and Pentium 4 systems.
In a spreadsheet, a defined block of cells. Rather than performing calculations on each cell individually, you can apply a formula to the whole range.
Roshal Archive. A format for storing compressed files.
A format for digital photos that stores the image exactly as the camera captured it, without compression or optimisation, but which is not compatible with all image editors.
Rewriteable Consumer Time Code. Used on camcorders and video recorders to keep track of recording length.
Rambus D-Ram. A design of memory claimed to offer very high performance, albeit at a high price. Developed by Rambus and licensed to Ram manufacturers, it is found in Pentium III and Pentium 4 systems.
Radio Data System. A feature of many radios, especially in cars, which can interpret coded data included with the radio signal to display the name of the radio station and interrupt other programmes with local traffic reports.
A file created during an application installation that contains useful information. Readme files are usually found in the same Program Files folder as the application.
The software required to play Real Audio and Real Video files streamed over the internet. A basic version is available as a free download while a more sophisticated version can be bought online.
Something that takes place on a computer at the same speed as it would in real life. In real-time games, perhaps a flight simulator, a minute or an hour of game time is the same as in the outside world. In real-time graphics processing, the on-screen image or video is rendered as you watch, rather than relying on a prerecorded picture.
To restart a computer. Normally, this is done by using the 'Restart' option on the Windows Start menu. However, it may be necessary to press Control-Alt-Delete or even to use the Reset button if one is fitted to the PC.
A single entry in a database, comprising a related group of individual 'fields'. Each entry in an address book, for example, is a record.
Standard for compact disc recordable format, or blank CDs onto which information, such as data or music, can be recorded once. Playable on most CD-Rom drives and CD players. You need a CD-R drive to record onto CD-R discs.
Where all files deleted in Windows are sent. Shown as a rubbish bin icon on the Desktop, it must be emptied if you want to get rid of deleted files for good.
The effect that appears on some flash photographs by which some people's eyes appear red. Most modern photo-editing software and some cameras are able to remove the red colouring.
Measured in Hertz (Hz), the number of times per second that the image on your monitor is redrawn. Slight changes in the image each time it is updated combine to give the illusion of movement. For a steady image, the higher the refresh rate, the less flicker you will see. A refresh rate over 85Hz is generally accepted as being flicker-free.
A file integrated into Windows that stores information on all hardware and software installed on your PC. The Registry can be edited to tweak settings but incorrect changes can damage the PC.
A broadcast transmitter that relays or repeats the signal of another radio or television station, usually to an area not covered by the signal of the original transmitter.
A way of controlling one computer from another, over a network or the internet. Once useful for helping friends or family with technical support, but now superseded.
Disk drives that use high-capacity disks that can be removed and stored remotely.
Pressing and holding a key on the keyboard types that character onscreen repeatedly until you let go. The speed at which the character appears onscreen is called the repeat rate and it can be as fast or as slow as you want.
A central location where software is stored.
In an inkjet printer, the part that holds the ink. In many inkjets, the reservoir is combined with the printhead itself to create a single disposable unit, while others have replaceable reservoirs.
The amount of detail shown in an image, whether on screen or printed.
A Windows backup of system files and settings.
A kind of warranty in which, if it breaks, the computer must be returned to the maker for repair. Most of the time the return postage will be free, but check with the company.
A sound effect that adds the sound of a real environment, such as a room, hall, or cathedral, to create an illusion of depth in the music.
Radio Frequency Identification. A tiny chip that can be implanted into goods, animals and even people, which transmits information about the item it is attached to. The Pet Passport scheme uses RFID chips to identify animals.
A colour picture created on a monitor, by combining a value for red, green and blue channels to determine the colour of each individual pixel.
An interface for various Microsoft programs that arranges related tools into a series of tabs. The ribbon replaces toolbars and was introduced in Office 2007.
While most actions in Windows are performed by clicking the left mouse button, clicking the right mouse button displays a pop-up menu with special functions and options.
Rambus Inline Memory Module. A 'stick' of RD-Ram, used in Pentium III and Pentium 4 systems with suitable motherboards.
An audio effect that produces metallic or clanging sounds. The most famous example is the voices of the Daleks in Doctor Who.
To digitally copy the music data from a CD-Rom or audio CD. Ripping a track from an audio CD is the first stage of compressing it as an MP3 file.
Reduced Instruction Set Computer processors are designed using a very limited number of simple instructions. They can combine these instructions at high speed to perform much more complex calculations.
Registered Jack-11. The type of small plug and socket used by modems to connect to a telephone socket. A converter plug is needed before an RJ-11 cable can be plugged into a standard UK telephone socket (RJ-11 is a US standard).
Root Mean Squared. A way of measuring the power output of speakers. Because the calculation gives values similar to normal use, it is the most honest way of quoting speaker power output and the best way of comparing different models.
Making mobile phone calls when abroad. You must ask your mobile phone provider to enable roaming, and your operator must have a roaming agreement with the foreign operator. Your phone must be able to use the network technology in the foreign country.
Read-only memory. Any memory that can be read but not written to. A PC's Bios uses Rom to store basic system information and instructions that cannot be changed.
The default name of the administrator user, with full rights to manage a Linux installation.
Software that gives a malicious user administration rights and access to a computer.
A device used to connect more than one computer or other device to the internet.
An internet encryption and authentication system that uses an algorithm developed in 1977 by Ron Rivest, Adi Shamir, and Leonard Adleman. The RSA algorithm is widely used online to protect account details and suchlike.
Really Simple Syndication. A simple format for automatically distributing news headlines and other content from the web.
Real-time clock. The battery-powered clock inside every PC that keeps track of time while the system is switched off.
Rich Text Format. A file format used to transfer files between different types of word-processing programs. It preserves most of the formatting of a document.
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