Safe Mode: A way of entering Windows, primarily for diagnostics and repairs, that bypasses many of the drivers that can cause Windows failures.

satellite: One of the fastest means of connecting to the Internet, by using an outdoor antenna and a subscription to a satellite service.

scanner: A device that attaches to a computer and can create a graphics file of an object you place on the scanner (much like a photocopier, only a scanner produces a file rather than a paper copy).

screen: The part of the computer monitor on which information is displayed.

screen shot: An image of the screen's contents.

Scroll Lock: A key on a computer’s keyboard that, when pressed and therefore active, reverses the function of the cursor keys in some spreadsheet applications.

SDRAM: Also called SyncDRAM, these memory modules take the form of standard DIMMs. This kind of module is too slow for current PC use.

serial port: An older kind of versatile computer port that can connect a variety of devices to the PC; it has been largely replaced with USB ports.

shadow copies: Available in Vista Business, Enterprise, and Ultimate, shadow copies are a type of backup file that automatically saves all previous versions of files.

SIMM: Single Inline Memory Module; a type of memory module that often needs to be added in pairs.

Sleep mode: A state in which the computer slips into a special, power-saving setting, like going into a low-power coma.

Snipping Tool: Vista's built-in tool for creating screen shots.

software: Instructions that tell the computer hardware what to do or how to act; the brains of the computer.

Software Explorer: A tool within Windows Defender that can be used to control which applications run during the Windows startup process.

sound card: A circuit-filled gadget that plugs inside your PC to add music and explosions to computer games.

spatial imaging: A sound card feature that creates a 3D feeling to the sound being produced by your computer.

SPDIF: A computer connection, which requires special fiber optic cable, that’s used for digital audio.

SSID: Service Set Identifier; the name by which your wireless network is known.

standard: Specifications about how a group of network devices communicate.

stylus: A kind of mouse that looks like a pen and draws on a special pad, which translates to the computer display.

subwoofer: A speaker box designed for low-frequency sounds, which gives oomph to the bass in music or adds emphasis to the sounds in games.

SuperFetch: SuperFetch keeps track of which applications are being used the most on your computer and tries to pre-load those applications so they’re available before you need them.

surge protector: A special type of power strip that helps fight irregularities in the electrical supply that runs to your computer.

surround sound: 3D environmental audio, created by a set of speakers positioned around the listener.

S-Video: A type of computer connection that allows you to attach an S-Video monitor, video recorder, or television to your PC.

switch: A device that connects computers in a network and manages the signals between those computers.

system tray: The icons on the right side of the Windows taskbar that indicate what programs are running in the background.

system unit: The main box of the PC; also called the console.