save - Writing data to disk in order to preserve its contents. The first thing you must learn before using a program.

scanner - An input device that reads images or text and converts the data into digital signals.

scsi {SKUZ-zee} [small computer system interface] - Powerful and flexible peripheral-connect interface for hard disks, CD-ROM drives, tape drives, and scanners to computers.

SDRAM {ess-dee-ram} [static dynamic random access memory] - Random access memory which is called "static" because it will retain a value as long as power is supplied, unlike dynamic random access memory (DRAM) which must be regularly refreshed. SDRAM is faster than DRAM.

search engine - Web-based program that allows users to search for and retrieve specific information from the World Wide Web. The search engine may search the full text of web documents or a list of keywords, or use librarians who review web documents and index them manually for retrieval. Typically, the user types a word or phrase, also called a query, into a search box, and the search engine displays links to relevant web pages

search hijacker – any software that resets your browser's settings to point to other sites when you perform a search. Hijacks may reroute your info and address requests through an unseen site, capturing that info. In such hijacks, your browser may behave normally, but be slower. Search results when such a hijacker is running will sometimes differ from non-hijacked results.

secondary cache - (see "L2 cache")

sector - On a disk, a segment of one of the concentric tracks encoded on the disk; usually containing 512 bytes of data.

Secure Digital (SD) - A flash memory card format developed by Matsushita, SanDisk and Toshiba for use in portable devices, including digital cameras, handheld computers, PDAs and GPS units. As of 2006, SD card capacities include 8MB, 16MB, 32MB, 64MB, 128MB, 256MB, and 512MB, 1GB, 2 GB, 4 GB, 6 GB, 8 GB (4-32 GB: SDHC)[1] and 32GB.(May be outdated)

The format has proven to be very popular. However, compatibility issues between older devices and the newer 4 GB and larger cards and the SDHC format[2] have caused considerable confusion for consumers.

secure server - A Web server that supports any of the major security protocols, like SSL, that encrypt and decrypt messages to protect them against third party tampering.

Secure Sockets Layer (SSL) - protocol that allows mutual authentication between a client and a server for the purpose of establishing an authenticated and encrypted connection. SSL runs above TCP/IP and below HTTP, LDAP, IMAP, NNTP, and other high-level network protocols. The new Internet Engineering Task Force (IETF) standard called Transport Layer Security (TLS) is based on SSL

security certificate - information (often stored as a text file) that is used by the SSL protocol to establish a secure connection.

security device - Hardware or software that provides cryptographic services such as encryption and decryption and can store certificates and keys. A smart card is one example of a security device implemented in hardware. Each security device is protected by its own master password.

serial port [com port] - A connector on a computer to which you can attach a serial line connected to peripherals which communicate using a serial (bit-stream) protocol.

server - Computer that provides some service for other computers connected to it via a network. The most common example is a file server which has a local hard disk and services requests from remote clients to read and write files on that disk.

server authentication - process of identifying a server to a client by using a server SSL certificate.

server SSL certificate - certificate that a server presents to a client to authenticate the server's identity using the Secure Sockets Layer (SSL) protocol.

SGML [Standard Generalized Markup Language] - A generic language for writing markup languages.SGML makes possible different presentations of the same information by defining the general structure and elements of a document. HTML (Hypertext Markup Language) is based on SGML.

SGRAM {ess-gee-ram} [Synchronous Graphic Random Access Memory] - Memory used for graphic-intensive operations such as 3-D rendering and displaying full-motion video.

S-HTTP - An extension to the HTTP protocol to support sending data securely over the World Wide Web.

shadow copy - In a generic sense, it refers to an identical instance of an entity created for the purpose of backup.

Shadow Copy (also called Volume Snapshot Service or VSS) is a feature in recent versions of Microsoft Windows that allows taking manual or automatic backup copies or snapshots of a file or folder on a specific volume at a specific point in time. Users can also create "shadow copies" by setting a System Protection Point using the System Protection tab in the System control panel. The user can be presented multiple versions of a file throughout a limited history and be allowed to restore, delete, or copy those versions. This feature is available only in the Business, Enterprise, and Ultimate editions of Windows Vista and is inherited from Windows Server 2003.

Sidebar - (see Windows Sidebar)

signature - A text file, usually only a few lines, which has the name of the user, and sometimes contact information, which is automatically attached to e-mail messages and newsgroup postings. Some people include ASCII art, slogans, or favorite quotations in their signatures.

signing certificate - certificate whose corresponding private key is used to sign transmitted data, so that the receiver can verify the identity of the sender. Certificate authorities (CAs) often issue a signing certificate that will be used to sign email messages at the same time as an encryption certificate that will be used to encrypt email messages.

signing key - private key used for signing only. A signing key and its equivalent public key, together with an encryption key and its equivalent public key, constitute dual key pairs.

SIMM {simm} [Single Inline Memory Module] - Computer plug-in memory module, usually containing 3 or 9 chips. One edge of the rectangular package has a card-like connector for plugging it into the motherboard.

single-lens reflex (SLR) {ess-ELL-ahr} - The single-lens reflex (SLR) camera is a photographic imaging instrument that uses an automatic moving mirror system and viewing pentaprism, which is situated between the lens and the film plane to direct the light reflected from the subject's image, then passing through the attached lens, with the light being reflected by the 45 degree angle mirror to the optical pentaprism, where the light is again reflected two more times until it passes through the viewfinder lens. The image can then be composed by the photographer; the focus can be adjusted manually (or automatically) by either the photographer or the autofocus system; and then the photographer can release the shutter, thereby exposing the film (or, in the case of a DSLR, the CCD or CMOS imaging sensor). The viewfinder includes a matte focusing screen located just above the mirror system to diffuse the light, then to allow the light into the pentaprism, where it is reflected and then through the viewfinder lens to the photographer's eye. This system permits accurate viewing, composing and focusing, especially useful with interchangeable lenses.

The digital versions of SLRs work in this manner: the shutter retracts so an image can be recorded. One of the prime benefits of using a digital SLR camera is that lenses are interchangeable.

SIP {sip} [Single Inline Package] - Computer plug-in memory module, containing 3 or 9 chips. One of the long edges of the rectangular package has pins for plugging into the motherboard.

slash (/) [forward slash] - DOS symbol used to separate command line options that alter the default settings for a DOS command. (compare "backslash")

SLIP {slip} [Serial Line Internet Protocol] - Standard for using a regular telephone line and a modem to connect a computer as a real Internet site. SLIP is gradually being replaced by PPP.

SLR - (see "single-lens reflex")

smart card - small device, typically about the size of a credit card, that contains a microprocessor and is capable of storing cryptographic information (such as keys and certificates) and performing cryptographic operations.

SMTP {ess-em-tee-pee} [Simple Mail Transfer Protocol] - Internet protocol for transferring e-mail from one server to another until it is delivered to the recipient.

snail mail - Mail that is delivered to a box mounted on a post outside a house, business, or apartment.

sneakernet - A means of moving a file from one computer to another by putting it on a floppy disk and carrying it across the room (possibly while wearing sneakers).

SNMP [Simple Network Management Protocol] - Set of communication standards for devices connected to a TCP/IP network. Examples include routers, hubs, and switches.

soft boot - Restarting the computer without turning the power off. (opposite of "hard boot")

software - System, utility or application programs expressed in a computer-readable language.

sound card - Computer device for reproducing sounds through external speakers.

spam [or spamming] - An inappropriate attempt to use a mailing list or other networked communications facility as if it was a broadcast medium (which it is not) by sending the same message to a large number of people who didn't ask for it. The electronic equivalent of junk mail. (From the Monty Python sketch of the same name.)

spamdex - To stuff a Web page full of words in the hope of making it high on the list for search engine robots. Sometimes a Web page will have a list of many words, or the same word repeated many times, with the text in the same color as the background. Spamdexing will cause a Web page to be kicked from search engine indexes.

spam tool – any software designed to extract e-mail addresses from Web sites and other sources, and/or efficiently send unsolicited (and perhaps untraceable) mail to these addresses.

spreadsheet - Application program that manipulates numerical and string data in rows and columns of cells. The value in a cell is calculated from a formula which can involve other cells.

spoof - to forge your identity. Attackers use spoofers to forge their IP address (IP spoofing).

spoofing - Pretending to be someone else. For example, a person can pretend to have the e-mail address bill@microsoft.com, or a computer can identify itself as a site called www.microsoft.com when it is not. Spoofing is one form of misrepresentation

spyware – is any product that employs a user's Internet connection in the background without their knowledge, and gathers/transmits info on the user or their behavior. Many spyware products will collect referrer info (information from your Web browser that reveals from what Internet address you linked to the site), your IP address (a number that is used by computers on the network to identify your computer), system information (such as time of visit, type of browser used, the operating system and platform, and CPU speed.) Spyware products sometimes wrap other commercial products, and are introduced to machines when those commercial products are installed.

spyware cookie – any cookie that is shared among two or more unrelated sites for the purpose of gathering and sharing private user information.

SSL {ess-ess-ell} (See "Secure Sockets Layer")

Start Button - Click on this button (or press the CTRL key and the Esc key) to access the Start Menu.

Start Menu - Menu system that provides instant access to recently opened documents, computer settings, installed programs, help, favorite Internet sites, and the Shut Down menu. Also included are the Find tool to locate files, folders, computers, networks and Web sites; the Run box that provides the ability to launch applications; and the Log Off tool to change to a different user.

startup disk - (see "boot disk")

startup folder - In Windows, a folder on the Start Menu containing programs that will automatically execute when Windows starts.

streaming - Playing audio or video immediately as it is downloaded from the Internet, rather than storing it in a file on the receiving computer first. Streaming is accomplished by way of Web browser plug-ins, which decompress and play the file in real time; a fast computer and fast connection are necessary.

subject - entity (such as a person, organization, or router) identified by a certificate. In particular, the subject field of a certificate contains the certified entity's subject name and other characteristics.

subordinate CA - certificate authority (CA) whose certificate is signed by another subordinate CA or by the root CA.

surge protector - An electrical device that protects a computer from spikes and surges in the power line and has outlets for several electrical plugs.

SVGA [Super Video Graphics Array] - Extension of the VGA video standard that supports resolutions of 1,024 by 768 pixels and higher with up to 16.7 million simultaneous colors.

symmetric encryption - encryption method that uses a single cryptographic key to both encrypt and decrypt a given message.

synchronous - Two or more processes that depend upon the occurrences of specific events such as common timing signals.

syntax - structure of strings in some language.

system.ini - Windows initialization file that contains information about the system's hardware and the internal Windows operating environment. (compare "win.ini")

System Restore - a component of Microsoft's Windows Millennium Edition, Windows XP, and Windows Vista operating systems that allows for the rolling back of system files, registry keys, installed programs, etc., to a previous state in the event of a failure. In Windows Vista, System Restore features an improved interface and is now based on Shadow Copy technology. In prior Windows versions, it was based on a file filter that watched changes for a certain set of file extensions, and then copied files before they were overwritten.