The unit of data sent across a packet switching network. While some Internet literature use the term to refer specifically to data sent across a physical network, other literature views the Internet as a packet switching network and describes IP Datagrams as packets.

A software tool used by programmers. It shows what packets of information are sent to and from a computer.

Data transmission process, utilizing addressed packets, whereby a channel is occupied only for the duration of the packet transmission. SDSUnet is a are packet-switching network.

The oldest and most limited Macintosh graphic file format, holding only black-and-white bit maps at 72 dpi. Paint files (file type PNTG) are limited to 8 by 10 inches.

A cable used to connect peripheral devices through a computer΄s parallel port. A type of port that transmits data in parallel (several bits side by side).

A word, number, or symbol that is typed after a command to further specify how the command should function.

A check bit used to make the sum of the bits in a unit of data either even or odd (including the parity bit). A unit of data that is 8 bits long would have no parity, and a unit of data 7 bits long would have an even parity bit to make an 8-bit word. Parity is used to check a unit of data for errors during transmission through phone lines or null modem cables.

A code used to gain access to a locked system. Good passwords contain letters and non-letters and are not simple combinations such as virtue7. A good password might be:

To insert information from the Clipboard. Information can be pasted multiple times.

A route used in finding, retrieving, and storing files on a disk. The course leading from the root directory of a drive to a particular file.

A standard format for credit-card-size expansion cards, used to add features to laptop computers, handheld computers, and desktop computers. The acronym stands for Personal Computer Memory Card International Association.

Portable Document Format. A PDF file is an electronic facsimile of a printed document.

Μέθοδος στησίματος δικτύων υπολογιστών που επιτρέπει σε κάθε χρήστη να στείλει και να λάβει δεδομένα χωρίς να απαιτεί την ύπαρξη ενός κεντρικού server.

A piece of hardware that΄s outside the main computer. It usually refers to external hardware such as disk drives, printers, and scanners sold by a third party.

Practical Extraction and Report Language. Γλώσσα προγραμματισμού για [CGI scripts].

Widely-used encryption software from PGP Security. The initials stand for Pretty Good Privacy.

Picture element. Digital images are composed of touching pixels, each having a specific color or tone. The eye merges differently colored pixels into continuous tones.

A means of reducing image resolution by simply deleting pixels throughout the image.

A (usually small) piece of software that adds features to a larger piece of software. Common examples are plug-ins for the Netscape? browser and web server. Adobe Photoshop? also uses plug-ins. The idea behind plugin?s is that a small piece of software is loaded into memory by the larger program, adding a new feature, and that users need only install the few plug-ins that they need, out of a much larger pool of possibilities. People other than the publishers of the software usually create plug-ins the plug-in works with.

Photo multiplier tube. The light sensing device generally used in drum scanners.

(Point of Presence, also Post Office Protocol) -- Two commonly used meanings: Point of Presence and Post Office Protocol. A Point of Presence usually means a city or location where a network can be connected to, often with dial up phone lines. So if an Internet company says they will soon have a POP in Belgrade, it means that they will soon have a local phone number in Belgrade and/or a place where leased lines can connect to their network. A second meaning, Post Office Protocol refers to the way e-mail software such as Eudora gets mail from a mail server. When you obtain a SLIP, PPP, or shell account you almost always get a POP account with it, and it is this POP account that you tell your e-mail software to use to get your mail.

One of several rendezvous points where TCP/IP connections can be made on a computer. Ports are numbered, with several locations reserved for specific types of network activity, such as telnet on port 23, HTTP traffic on port 80 and USENET news (NNTP) on port 119.

Usually used as a marketing term to described a Web site that is or is intended to be the first place people see when using the Web. Typically a "Portal site" has a catalog of web sites, a search engine, or both. A Portal site may also offer email and other service to entice people to use that site as their main "point of entry" (hence "portal") to the Web.

A single message entered into a network communications system. E.g. A single message posted to a newsgroup or message board. See Also: Newsgroup

Pixels per inch or pixels per centimeter. Units of measurement for scanned images.

(Point to Point Protocol) -- It provides a method for transmitting packets over serial point-to-point links. Most well known as a protocol that allows a computer to use a regular telephone line and a modem to make TCP/IP connections and thus be really and truly on the Internet.

Parameter RAM (pronounced pee-ram). A small portion of the Mac΄s RAM set aside to hold basic information such as the date and time, speaker volume, desktop pattern, and keyboard and mouse settings. PRAM is powered by a battery, so it doesn΄t lose the settings when you shut down. Sometimes, however, the PRAM data gets corrupted, causing crashes or other problems.

The color characteristics of an input or output device, used by a CMS to ensure color fidelity.

Information about an object, including settings or options for that object. For example, you look at properties of a file for information such as the file size, file type, and file attributes.

When data is being transmitted between two or more devices something needs to govern the controls that keep this data intact. A formal description of message formats and the rules two computers must follow to exchange those messages. Protocols can describe low-level details of machine-to-machine interfaces (e.g., the orderin which bits and bytes are sent across wire) or high-level exchanges between application programs (e.g., the way in which two programs transfer a file across the Internet).

It masks a computer going out on the web. In many corporate or institutional networks, all requests for web pages go through a proxy server.

Packet Switch Node; a store-and-forward packet switch (formerly called an IMP).

(Public Switched Telephone Network) -- The regular old-fashioned telephone system.