Scalability The capability of increasing the computing capacity of a Web site or computer system by adding more processors or more powerful processors. This in turn, increases the site's or server's ability to process more operations or transactions in a given period of time. Traditionally, scalability has been achieved by adding or changing to one or more large, multi-processors servers. A newer approach is to add al lot more smaller servers.
Scan code A code sent from the keyboard to the computer telling it which key has been pressed or released. The keyboard interrupt then converts the scan code into ASCII codes, extended codes and settings in the status bytes that keep track of things like the Shift keys.
Screen Resolution The number of pixels that can be displayed on the screen. Expressed as a count in the horizontal direction by the vertical (eg. 1024 x 768).
Screen shot Screen shots, screen dumps, and screen captures are all the same thing: an image of what appears on the screen. Most computers have a way to send a basic screen shot directly to a disk file or to a printer. Some specialised graphics programs let you choose just which part of the screen to shoot.
Script Programs can come in different forms. One form called a script involves a text file consisting of a list of commands. They are programs in the sense that they perform a function or set of functions when launched. You may not know it, but you pretty much run into scripts every time you get on the Internet.
Scroll bar A small area that appears down the right side and/or at the bottom of a window when the contents of the window are larger than the window itself. The scroll bar allows the user to move up, down, left or right to view the information that is not seen in the window.
Scrolling The vertical or horizontal movement of on-screen data so that data that cannot be displayed will be brought onto the screen.  Scroll bars are provided to allow scrolling to be done.
SCSI Small Computer System Interface (SCSI) is a device connection used for hard drives. It is normally used in servers or workstations which require faster access to the data on the disk (eg. advanced multimedia or graphics work). The advantage of SCSI over other methods (like IDE) is that SCSI is faster, can recover from errors better and you can have more devices connected to the SCSI bus.
SDMI The Secure Digital Music Initiative is a specification for playing digital music. Where the popular MP3 specification focuses only on music quality in the most compact file size, the recording-industry's SDMI adds security. The goal is for future generations of digital music players to be able to handle both free MP3 files (which SDMI supports) and paid-for SDMI music files (which can't be copied).
SDRAM Synchronous Dynamic RAM (SDRAM) is memory which accesses the data in time with the memory bus clock. This results in a memory access with each clock tick.
Sector A portion of a track on a disk.
Secure Sockets Layer A protocol that ensures message transmissions sent over the Internet are kept secure. When you purchase a book online,  you want your credit card number to be secure when you make your purchase. The data will be encrypted. When SSL is activated, you should see a picture of a lock (unbroken) at the bottom right hand corner of your browser window.
Seek Time A term used mainly with disk drives that quantifies the time taken to position the read/write head over a specific cylinder or track on the disk.
Shared-disk cluster A cluster in which all systems access the same centralised storage system but us their own memory and processing power.
Shared-everything cluster A cluster in which systems are integrated into a single logical system in which any system can access the memory or storage of any other system.
Shared-nothing cluster A cluster in which the systems each have their own storage, processing power and other resources, but exchange information using standard messages.
Shareware Shareware is software that is distributed using an honour system. Most shareware can be obtained for no cost but the author will usually request a payment if you like or continue to use the program. Generally, you can copy and pass shareware on to friends and family assuming that if they continue to use it that they will pay the necessary fee also.
SIG Acronym for Special Interest Group. This is typically a group of people who are members of a PC User Group who have meetings relating to a special subject that they have an interest in. For example, a PC User Group may have a SIG relating to Databases, another for Word Processing, etc.
Signature A signature is a few lines you can set to appear at the end of every e-mail you send, containing your name/address/phone number, a sales pitch, or a quote you think your e-mail correspondents will enjoy reading.
Site map A site map is a visual model of everything on a web site.
Skins Some programs allow us to switch the look of program's interface on-the-fly (ie. colours, textures, etc.). This is what we call skinning and skins are the files that can be applied to an application (like Winamp) to change its look.
Slack space The unused space at the end of a cluster when a file does not use the entire cluster.
SMART Self-Monitoring Analysis and Reporting Technology (SMART) is a system that alerts you if the hard drive is about to fail so that you can back it up before it actually fails.
SMP Symmetric Multi Processor. A system which has more than one CPU.
SMS SMS (Short Message Service) is a way to send text messages of up to 160 characters to a mobile phone or other SMS-enabled device.
SMTP The Simple Mail Transport Protocol (SMTP) specifies how e-mail moves over computer networks. It's "simple" in that this protocol works only for text. If you want to e-mail other information, you need a different protocol, such as MIME (Multipurpose Internet Mail Extensions).
Snail mail Computer slang referring to traditional postal mail that Australia Post handles.
SneakerNet Jargon for "sneaker network," is the phrase that techies use to describe the practice of carrying files on floppies from one computer to another instead of transmitting them over a real network.
SOAP Acronym for Simple Object Access Protocol. It is an XML protocol that allows any program running on one type of operating system to communicate with a program running on another operating system via a Web service. For example, a Windows-based PC could semalessly communicate with a Unix server.
SPA SPA (or Secure Password Authentication) is a more secure way of signing on to an e-mail account. SPA forces your computer to assure the main e-mail server computer that you truly are who you say you are so that others can't pose as you to send and receive your e-mail or intercept your password.
Spamdex A "spamdex" is a block of text, usually hidden on a home page (typed in the same colour as the home page background), that includes either:
1) multiple instances of the same keyword so that the home page appears at the top of the list generated by a search on that keyword, or
2) hundreds of related and not-so-related words so that the page appears in the results of more keyword lists.
Spider Also called a Web spider, is a software program that regularly searches (or "crawls") through the Internet, indexing all the text in all the pages on the Web. Spiders allow search services to keep up with the new content being added to the Web, without having to depend on the creators of that content to index it themselves.
Spike An instantaneous dramatic increase in voltage.
Spindle A "spindle" is the axle, or shaft, around which a computer disk revolves. Technocrats also use "spindle" interchangeably with "disk drive". For example, when a nerd refers to a "three-spindle" laptop, he or she means a laptop with three disk drives (typically a hard, floppy, and CD-ROM drive).
Splash screen The very first screen or image that you seewhen you enter a Web site, start your computer or a program on it.
Spyware Spyware is a program that gathers personal information from a person's computer without him or her knowing about it. Spyware can often be found under the guise of "adware," or a program that uses internal banner advertisements to pay for itself.
SQL Acronym for Structured Query Language. It is a standardised language used to interrogating or requesting information from a database.
SRAM Static RAM (SRAM) is a very fast type of memory, normally used only for cache memory.
SSID Acronym for Service Set IDentifier.  The SSID is what differentiates one wireless computer network from others that may be operating within the same area.  It does not provide any security as the SSID is openly broadcasted out and any wireless device can detect what it is.
SSL SSL, or Secure Sockets Layer, is a way for two communicating Internet programs to keep their exchanges secret. SSL ensures encrypted and authenticated communications for Web browsers, newsreaders, and other such software. Many Web shopping sites use SSL connections.
Status bar A section of a program's window (normally at the bottom) that displays relevant information for that program.
Storage Area Network Otherwise known as a SAN, it is a high-speed network for interconnecting different kinds of storage devices such as tape libraries and disks which can be shared by all users through a network server.
Streaming Media Used on web sites to deliver audio/video using a method where the information is downloaded from the Internet in a continuous stream, instead of waiting for the entire video to download. An example of software which uses streaming media is Real Player.
Subdomain A domain is the "something" in an address of It is the top level of an address. A subdomain is the "lowerlevel" in an address of If you own a domain, you own all the subdomains.
Surge A short term increase in voltage.
Surge Protector A device that protects your computer against spikes (sudden, short rises) or surges (longer rises) in the electrical or telephone lines. This protection is important because these spikes and surges can seriously damage your data and your computer's components.
Swap Otherwise known as Swap Space, Swap File or Virtual Memory. An area of disk set aside for the storing of data not needed in memory but may be needed later. Some operating systems run better when the swap space is on a partition of its own (eg. Linux).
Switch A network device that selects a path or circuit for sending data.
Symmetrical Multiprocessing A hardware design concept for parallel computing where multiple procesors run a single copy of the operating system and share the memory and other resources of one computer. With symmetrical multiprocessing, all processors have equal access to memory, I/O and external interrupts.
Synchronous DRAM see SDRAM
Syntax The rules which regulate the structure of expressions and statements in a programming language.
System Area The first sectors on a disk where the OS stores the control information it needs to access the files on the disk, including the partition table, File Allocation Table (FAT) and root directory/folder.
System Tray The little section at the bottom right hand corner of your screen is known as the system tray (or "systray"). This tray is just a small part of a much larger world known as the "Taskbar" (the bar at the bottom of your screen) and is used to display icons for programs that tend to be an integral part of the running of the system (eg. anti-virus programs, etc).


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This page was last updated on Sunday, 14 December 2008