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I.T. Glossary
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American Standard Code for Information Interchange. A code supported by just about every computer manufacturer to represent letters, numbers and special characters.
A loosely defined set of technologies developed by Microsoft. ActiveX is an outgrowth of two other Microsoft technologies called OLE (Object Linking and Embedding) and COM (Component Object Model). As a moniker, ActiveX can be very confusing because it applies to a whole set of COM-based technologies. Most people, however, think only of ActiveX controls, which can be automatically downloaded and executed by a web browser.
A unique number or name assigned to all computers that are connected to the Internet. See also domain name and IP address.
A DSL line where the upload speed is different from the download speed. Usually the download speed is much greater.
See also: Download, DSL, SDSL, Upload
Downloading files from a machine which lets you log in without having an account or a user id. The word anonymous is used as the login id and your email address is used as the password. See also file transfer protocol (FTP).
See also: FTP
The Australian Academic and Research Network (AARNet) is a major part of the Australian section of the Internet.
This is the defacto world-wide standard for the code numbers used by computers to represent all the upper and lower-case Latin letters, numbers, punctuation, etc. There are 128 standard ASCII codes each of which can be represented by a 7 digit binary number: 0000000 through 1111111.
A high-speed line or series of connections that forms a major pathway within a network. The term is relative as a backbone in a small network will likely be much smaller than many non-backbone lines in a large network.
See also: Network
How much stuff you can send through a connection. Usually measured in bits-per-second (bps.) A full page of English text is about 16,000 bits. A fast modem can move about 57,000 bits in one second. Full-motion full-screen video would require roughly 10,000,000 bits-per-second, depending on compression.
See also: Bit, bps, T-1
In common usage the baud rate of a modem is how many bits it can send or receive per second. Technically, baud is the number of times per second that the carrier signal shifts value - for example a 1200 bit-per-second modem actually runs at 300 baud, but it moves 4 bits per baud (4 x 300= 1200 bits per second).
See also: Bit, Modem
Information consisting entirely of ones and zeros. Also, commonly used to refer to files that are not simply text files, e.g. images.
See also: MIME, UUENCODE
-- (BINary HEXadecimal)
A method for converting non-text files (non-ASCII) into ASCII. This is needed because Internet e-mail can only handle ASCII.
See also: ASCII, MIME, UUENCODE
A single digit number in base-2, in other words, either a 1 or a zero. The smallest unit of computerized data. Bandwidthis usually measured in bits-per-second.
See also: Bandwidth, Bit, bps, Byte, Kilobyte, Megabyte
A measurement of how fast data is moved from one place to another. A 56K modem can move about 57,000 bits per second.
See also: Bandwidth, Bit
A Client program (software) that is used to look at various kinds of Internet resources.
See also: Client, Server, URL, WWW
A collection of wires through which data is transmitted from one part of a computer to another. You can think of a bus as a highway on which data travels within a computer. When used in reference to personal computers, the term bus usually refers to internal bus. This is a bus that connects all the internal computer components to the CPU and main memory.
A byte is equal to a single letter of character in a computer file. One kilobyte is roughly 1,000 bytes, about 1,000 characters, or a little less than half a page of text.
1,000 bytes = 1Kb (kilobyte)
1,000 kilobytes = 1 Mb (megabyte)
1,000 megabytes = 1 Gb (gigabyte)
See also: Bit
A software program that is used to contact and obtain data from a Server software program on another computer, often across a great distance. EachClient program is designed to work with one or more specific kinds of Server programs, and each Server requires a specific kind of Client. A Web Browser is a specific kind of Client.
See also: Browser, Client, Server
Essentially the "brains" of your computer - the CPU actually executes instructions and processes data.
A computer program that requests services from a server running on a remote computer.
To obtain information about your computer's configuration, you can either:
* Click Start » Settings » Control Panel » System or
* Right click the My Computer icon on the Desktop, and click Properties.
The most common meaning of "Cookie" on the Internet refers to a piece of information sent by a Web Server to a Web Browser that the Browser software is expected to save and to send back to the Server whenever the browser makes additional requests from the Server.
Depending on the type of Cookie used, and the Browsers' settings, the Browser may accept or not accept the Cookie, and may save the Cookie for either a short time or a long time.
Cookies might contain information such as login or registration information, online "shopping cart" information, user preferences, etc.
When a Server receives a request from a Browser that includes a Cookie, the Server is able to use the information stored in the Cookie. For example, the Server might customize what is sent back to the user, or keep a log of particular users' requests.
Cookies are usually set to expire after a predetermined amount of time and are usually saved in memory until the Browser software is closed down, at which time they may be saved to disk if their "expire time" has not been reached.
Cookies do not read your hard drive and send your life story to the CIA, but they can be used to gather more information about a user than would be possible without them.
See also: Browser, Server
DHCP is a protocol by which a machine can obtain an IP number (and other network configuration information) from a server on the local network.
See also: IP Number, Network, Server
The software that handles communications to and from your computer to the Internet or any other computer, as well as packaging and unpackaging information for transmission.
The Domain Name System is the system that translates Internet domain names into IP numbers. A "DNS Server" is a server that performs this kind of translation.
See also: Domain Name, IP Number, Server
The unique name that identifies an Internet site. Domain Names always have 2 or more parts, separated by dots. The part on the left is the most specific, and the part on the right is the most general. A given machine may have more than one Domain Name but a given Domain Name points to only one machine. For example, the domain names:
matisse.net
mail.matisse.net
workshop.matisse.net
can all refer to the same machine, but each domain name can refer to no more than one machine.
Usually, all of the machines on a given Network will have the same thing as the right-hand portion of their Domain Names (matisse.net in the examples above). It is also possible for a Domain Name to exist but not be connected to an actual machine. This is often done so that a group or business can have an Internet e-mail address without having to establish a real Internet site. In these cases, some real Internet machine must handle the mail on behalf of the listed Domain Name.
See also: IP Number, TLD
Transferring data (usually a file) from a another computer to the computer you are are using. The opposite of upload.
See also: Upload
A method for moving data over regular phone lines. A DSL circuit is much faster than a regular phone connection, and the wires coming into the subscriber's premises are the same (copper) wires used for regular phone service. A DSL circuit must be configured to connect two specific locations, similar to a leased line (howeverr a DSL circuit is not a leased line.
A common configuration of DSL allows downloads at speeds of up to 1.544 megabits (not megabytes) per second, and uploads at speeds of 128 kilobits per second. This arrangement is called ADSL: Asymmetric Digital Subscriber Line.
Another common configuration is symmetrical: 384 Kilobits per second in both directions.
In theory ADSL allows download speeds of up to 9 megabits per second and upload speeds of up to 640 kilobits per second.
DSL is now a popular alternative to Leased Lines and ISDN, being faster than ISDN and less costly than traditional Leased Lines.
See also: ADSL, Bandwidth, ISDN, Leased Line, SDSL
Messages, usually text, sent from one person to another via computer. E-mail can also be sent automatically to a large number of addresses.
See also: Listserv ®, SMTP
A very common method of networking computers in a LAN.
There is more than one type of Ethernet. By 2001 the standard type was "100-BaseT" which can handle up to about 100,000,000 bits-per-second and can be used with almost any kind of computer.
See also: Bandwidth, FDDI, LAN
FAQs are documents that list and answerthe most common questions on a particular subject. There are hundreds of FAQs on subjects as diverse as Pet Grooming and Cryptography. FAQs are usually written by people who have tired of answering the same question over and over.
A combination of hardware and software that separates a Network into two or more parts for security purposes.
See also: Network
A floppy disk is a thin piece of magnetically coated mylar enclosed in a plastic jacket. Modern floppies are 3.5 inches in size and hold 1.44 Mb of data.
Such a disk is capable of storing approximately 1.4 million characters, or about 3,000 pages of information. This may sound like a lot, but it fills up surprisingly fast, especially if you have included graphics in your documents.
A very common method of moving files between two Internet sites.
FTP is a way to login to another Internet site for the purposes of retrieving and/or sending files. There are many Internet sites that have established publicly accessible repositories of material that can be obtained using FTP, by logging in using the account name "anonymous", thus these sites are called "anonymous ftp servers".
FTP was invented and in wide use long before the advent of the World Wide Web and originally was always used from a text-only interface.
See also: Login, WWW
The technical meaning is a hardware or software set-up that translates between two dissimilar protocols, for example America Online has a gateway that translates between its internal, proprietary e-mail format and Internet e-mail format. Another, sloppier meaning of gateway is to describe any mechanism for providing access to another system, e.g. AOL might be called a gateway to the Internet.
1000 or 1024 Megabytes, depending on who is measuring.
See also: Byte
Also referred to as the hard drive. The hard disk is a fixed disk located within the computer. Compared to floppy disks, hard disks are both faster and safer to use and will hold enormous amounts of data compared to a floppy disk. Computers sold now have hard disks ranging between 80 GB and 250 GB in storage capacity.
All the parts of the computer that you can "touch" or hold - for example, the keyboard, mouse, a memory chip.
The name assigned to a particular computer. When combined with the domain name, this forms the fully qualified domain name (which itself is often referred to as the domain name).
Any computer on a network that is a repository for services available to other computers on the network. It is quite common to have one host machine provide several services, such as SMTP (email) and HTTP (web).
See also: Network, SMTP
IMAP is gradually replacing POP as the main protocol used by email clients in communicating with email servers.
Using IMAP an email client program can not only retrieve email but can also manipulate message stored on the server, without having to actually retrieve the messages. So messages can be deleted, have their status changed, multiple mail boxes can be managed, etc.
IMAP is defined in RFC 2060
See also: Client, Email, POP, RFC, Server
The conduit through which data and instructions enter a computer. For example, the keyboard, a mouse, a joystick.
A global network of smaller computer networks that operate using the TCP/IP protocol suite.
IP Number -- (Internet Protocol Number)
Sometimes called a dotted quad. A unique number consisting of 4 parts separated by dots, e.g.
165.113.245.2
Every machine that is on the Internet has a unique IP number - if a machine does not have an IP number, it is not really on the Internet. Many machines (especially servers) also have one or more Domain Names that are easier for people to remember.
See also: Domain Name, Server, TCP/IP
The most widley used version of the Internet Protocol (the "IP" part of TCP/IP.)
IPv4 allows for a theoretical maximum of approximately four billion IP Numbers (technically 232), but the actual number is far less due to inefficiencies in the way blocks of numbers are handled by networks. The gradual adoption of IPv6 will solve this problem.
See also: IP Number, IPv6, Network, Protocol, TCP/IP
The successor to IPv4. Already deployed in some cases and gradually spreading, IPv6 provides a huge number of available IP Numbers - over a sextillion addresses (theoretically 2128). IPv6 allows every device on the planet to have its own IP Number.
See also: IP Number, IPv4, Network, Protocol, TCP/IP
Basically a way to move more dataover existing regular phone lines. ISDN is available to much of the USA and in most markets it is priced very comparably to standard analog phone circuits. It can provide speeds of roughly 128,000 bits-per-second over regular phone lines. In practice, most people will be limited to 56,000or 64,000 bits-per-second.
Unlike DSL, ISDN can be used to connect to many different locations, one at a time, just like a regular telephone call, as long the other location also has ISDN.
See also: DSL
An institution that provides access to the Internet in some form, usually for money.
Java is a network-friendly programming language invented by Sun Microsystems.
Java is often used to build large, complex systems that involve several different computers interacting across networks, for example transaction processing systems.
Java is also used to create software with graphical user interfaces such as editors, audio players, web browsers, etc.
Java is also popular for creating programs that run in small electronic devicws, such as mobile telephones.
Using small Java programs (called "Applets"), Web pages can include functions such as animations,calculators, and other fancy tricks.
See also: Applet, JDK
Still the most commonly used input device. Based on the standard character layout of a typewriter.
A thousand bytes. Actually, usually 1024 (210) bytes.
See also: Byte
A computer network limited to the immediate area, usually the same building or floor of a building.
See also: Network, VPN, WAN
A widely used Open Source Unix-like operating system. Linux was first released by its inventor Linus Torvalds in 1991. There are versions of Linux for almost every available type of computer hardware from desktop machines to IBM mainframes. The inner workings of Linux are open and available for anyone to examine and change as long as they make their changes available to the public. This has resulted in thousands of people working on various aspects of Linux and adaptation of Linux for a huge variety of purposes, from servers to TV-recording boxes.
See also: Open Source Software, Unix
Noun or a verb.
Noun: The account name used to gain access to a computer system. Not a secret (contrast with Password).
Verb: the act of connecting to a computer system by giving your credentials (usually your "username" and "password")
See also: Password
(or Mailing List) A (usually automated) system that allows people to send e-mail to one address, whereupon their message is copied and sent to all of the other subscribers to the maillist. In this way, people who have many different kinds of e-mail access can participate in discussions together.
See also: Email, Listserv
Technically speaking, a million bytes. In many cases the term means 1024 kilobytes, which is a more than an even million.
See also: Byte, Kilobyte
Also referred to as RAM, or Random Access Memory. Enables a computer to store, at least temporarily, data and programs. One way to think of memory is as the "working energy" available to the computer. Every program you run requires memory and there is only a finite amount of it. The more memory you have, the more programs you can have running simultaneously and the more data can be held for speedy access by your machine.
(Think of your computer as a person treading water in a swimming pool. Every time you open another program it's like giving that person a brick to hold. Too many bricks, and even the most powerful swimmer will sink!)
Unfortunately, memory does not "remember" your data! Memory is dynamic, so when the computer is switched off whatever programs or data that were in memory disappear. You must save your data to a storage device like a disk if you wish to keep it after the computer is turned off.
Originally a standard for defining the types of files attached to standard Internet mail messages. The MIME standard has come to be used in many situations where one cmputer programs needs to communicate with another program about what kind of file is being sent.
For example, HTML files have a MIME-type of text/html, JPEG files are image/jpeg, etc.
See also: HTML, JPEG
Generally speaking, "to mirror" is to maintain an exact copy of something. Probably the most common use of the term on the Internet refers to "mirror sites" which are web sites, or FTP sites that maintain copies of material originated at another location, usually in order to provide more widespread access to the resource. For example, one site might create a library of software, and 5 other sites might maintain mirrors of that library.
See also: FTP, WWW
A device that connects a computer to a phone line. A telephone for a computer. A modem allows a computer to talk to other computers through the phone system. Basically, modems do for computers what a telephone does for humans.
The maximum practical bandwidth using a modem over regular telephone lines is currently around 57,000 bps.
See also: Bandwidth, bps
The etiquette on the Internet.
Derived from the term citizen, referring to a citizen of the Internet,or someone who uses networked resources. The term connotes civic responsibility and participation.
Any time you connect 2 or more computers together so that they can share resources, you have a computer network. Connect 2 or more networks together and you have an internet.
See also: internet (Lower case i)
The name for discussion groups on USENET.
See also: USENET
Generally, any office that handles information for a network. The most famous of these on the Internet was the InterNIC, which was where most new domain names were registered until that process was decentralized to a number of private companies. Also means "Network Interface card", which is the card in a computer that you plug a network cable into.
See also: Domain Name, Network
The protocol used by clientand server software to carry USENET postings back and forth over a TCP/IP network. If you are using any of the more common software such as Netscape, Nuntius, Internet Explorer, etc. to participate in newsgroups then you are benefiting from an NNTP connection.
See also: Client, Server, TCP/IP
Any single computer connected to a network.
See also: Network
The operating system is a program specially written to manage the operations of the computer. The operating system is the interface between you, the software you use and the computer hardware. Windows 98 is an operating system, as is UNIX or MS-DOS. Apple Macintosh has its own operating system.
A display screen, printer, or other device that lets you see what the computer has accomplished.
Any external device attached to a computer. Examples of peripherals include printers, disk drives, display monitors, keyboards, mice and printers.
A hardware or software module that adds a specific feature or service to a larger system. For example, there are number of plug-ins for the Netscape Navigator browser that enable it to display different types of audio or video messages. Navigator plug-ins are based on MIME file types.
The Internet access node provided by an Internet access provider. Dial-up users connect to it over the phone line.
A computer on the internet using TCP/IP protocols uses various numbered "virtual" ports to differentiate between the various servers the computer may be running. In a standard setup the telnet server is assigned port 23, gopher is assigned port 70, and so on.(Note: These are not to be confused with the hardware ports in the back of your machine, where printers and other peripherals are attached.)
A protocol for using TCP/IP over a serial transmission line, such as a telephone line (with a modem). This is expected to replace SLIP in time. Most Internet Service Providers support both PPP and SLIP.
see Point-to-Point Protocol
The rules computers must follow to exchange messages. A protocol describes both the format of messages sent and the permitted method of response.
A proxy server is a computer on the local network (e.g. UQconnect, or your local ISP) which accesses the Internet on the user's behalf. Most ISPs provide proxy servers for all internet protocols (ie. ftp, http) A WWW proxy server retrieves web pages on behalf of a user and then passes them onto that user. This allows faster access to frequently requested pages stored in the network proxy cache, rather than accessing the remote site every time.
Intellectual property, including software, Web documents, images etc that are not protected by copyright or patent regulations and are freely available for use by anyone.
See Memory
A system that transfers information between two networks using the same set of protocols.
A computer on a network that manages network resources. For example, a file server is a computer and storage device dedicated to storing files. Any user on the network can store files on the server. Computers in the network rely on servers for resources, such as files, devices, and even processing power. You may have to identify yourself to the server with a username and password.
A set of step-by-step instructions created by humans which direct the computer to do the tasks you require and produce the desired results. These instructions may also be referred to as a program. An application is a program used for a specific purpose - for example, Word is a word-processing application, Excel is a spreadsheet application.
A protocol for using TCP/IP over a serial transmission line, such as a telephone line (with a modem). It is expected that this will be replaced by PPP in time. Most Internet Service Providers support both SLIP and PPP.
1. A computer program that allows a computer to provide services when requested by another computer. The requesting computer uses client software.
2. A computer which is running server software.
For example, a file server is a computer and storage device dedicated to storing files. Any user on the network can store files on the server. Computers in the network rely on servers for resources, such as files, devices, and even processing power. You may have to identify yourself to the server with a username and password.
Shareware is software that is generally free to download, but if you like and use it regularly you pay a registration fee to the software's author. Once the software has been registered, it is usually possible to receive free help and updates. Often, shareware is distributed in a limited version (such as a 30-day limit, or with some functions disabled) to allow users to get used to the software before paying the fee. The copyright for this software remains with the author. Shareware can be distributed to friends, but they are expected to follow the same rules, that is, if they like and use the software regularly they are asked to pay a registration fee.
See also: Freeware
See also: Serial Line Internet Protocol.
See also: Transmission Control Protocol/Internet Protocol.
Allows you to access applications available on a remote computer using the Internet as the connection between the computers. A mechanism for "remote login".
A set of rules about how messages are transmitted within and between individual computer networks. TCP/IP is the basis for all communication on the Internet.
See also: protocol
A destructive program that masquerades as a benign application. Unlike a viruses, Trojan horses do not replicate themselves but they can be just as destructive. Typically Trojan horse viruses are from email attachments that are small executable programs (like the little funny ones that are sent around) or downloaded from the Net.
Be careful of these attachments, the emails they come with are often written as though it is to a friend or work mate but don't mention any names or details as they have been bulk sent to millions of users. Most virus scanning software has an option to scan email attachments.
The term comes from a story in Homer's Iliad, in which the Greeks give a giant wooden horse to their foes, the Trojans, ostensibly as a peace offering. But afterthe Trojans drag the horse inside their city walls, Greek soldiers sneak out of the horse's hollow belly and open the city gates, allowing their compatriots to pour in and capture Troy.
A URL is the form of address used by the World-Wide Web. It identifies both the resource type and the location of documents on the Web. The format is usually: resource type://domain name/path.
The sending of a file from your computer to another remote computer.
see Uniform Resource Locator.
Short for Universal Serial Bus, an external bus standard that supports data transfer rates of 480 Mbps. A single USB port can be used to connect up to 127 peripheral devices.
A program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes. Most viruses can also replicate themselves. All computer viruses are manmade. A simple virus that can make a copy of itself over and over again is relatively easy to produce. Even such a simple virus is dangerous because it will quickly use all available memory and bring the system to a halt. An even more dangerous type of virus is one capable of transmitting itself across networks and bypassing security systems.
A type of computer virus that is encoded as a macro embedded in a document. Many applications, such as Microsoft Word and Excel, support powerful macro languages. These applications allow you to embed a macro in a document, and have the macro execute each time the document is opened. According to some estimates, 75% of all viruses today are macro viruses. Once a macro virus gets onto your machine, it can embed itself in all future documents you create with the application. Antivirus programs can protect your system against most macro viruses, although new ones are always being created that slip by the antivirus filters.
The entire collection of Web pages for a specific organisation, person or interest group.
See also: home page.
An Internet service that provides an integrated interface to most other Internet services and is based on hypermedia.
See also: World-Wide Web.
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Derecho de autor © Swann 2008 | Légal | Les termes d'Usage | Politique d'intimité | Contacter des Etats-Unis
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