Newsgroups are electronic discussion groups in which you can share information and opinions with people all over the world. Within each newsgroup, you'll find any number of articles on a given subject, and many subjects being discussed. Usenet newsgroups allow you to reply to articles you have read and to publish ("post") your own articles for others to read. Newsgroups are organized and grouped by title using compound names such as rec.sport.basketball.college. Here, rec specifies recreational topics, sport specifies a subgroup of recreation, and so on.

Back To Top

A system capacity constraint that may result in reduced data flow during peak load conditions.

Back To Top

A command for accessing limited account information for a user on a network. On some systems, finger only reports whether the user is currently logged on. Other systems return additional information, such as the user's full name, address, and telephone number. Of course, the user must first enter this information into the system. Many e-mail programs now have a finger utility built into them.

Note: Finger is limited to providing information such as the full name of the account holder and address information, intentionally made public by the account holder.

Back To Top

Short for Packet Internet Groper, PING is a utility used to determine whether a specific IP address is accessible. It works by sending a packet to the specified address and waiting for a reply. PING is used primarily to troubleshoot Internet connections. There are many freeware and shareware PING utilities available.

Back To Top

An IP address is an identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol route messages based on the IP address of the destination. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be ranged 0 to 255. For example, 1.160.10.240 could be an IP address.

Back To Top

A packet is a piece of a message transmitted over a packet-switching network. One of the key features of a packet is that it contains the destination address in addition to the data. In IP networks, packets are often called datagrams.

Back To Top

Freeware is copyrighted software given away for free by the author. Although it is available for free, the author retains the copyright, which means that you cannot do anything with it that is not expressly allowed by the author. Usually, the author allows people to use the software, but not sell it.

Back To Top

Shareware is software distributed on the basis of an honour system. Most shareware is delivered free of charge, but the author usually requests that you pay a small fee if you like the program and use it regularly. By sending the small fee, you become registered with the producer so that you can receive service assistance and updates. You can copy shareware and pass it along to friends and colleagues, but they too are expected to pay a fee if they use the product.

Back To Top

Integrated Services Digital Network (ISDN) is an international communications standard for sending voice, video, and data over digital telephone lines or normal telephone wires. ISDN supports data transfer rates of 64 Kbps (64,000 bits per second). Most ISDN lines offered by telephone companies give you two lines at once, called B channels. You can use one line for voice and the other for data, or you can use both lines for data to give you data rates of 128 Kbps, three times the data rate provided by today's fastest modems.

The original version of ISDN employs baseband transmission. Another version, called B-ISDN, uses broadband transmission and is able to support transmission rates of 1.5 Mbps. B-ISDN requires fiber optic cables and is not widely available.

Back To Top

A type of digital data transmission in which each medium (wire) carries only one signal, or channel, at a time. Most communications involving computers uses baseband transmission. This includes communications from the computer to devices (printers, monitors, and so on), communications via modems, and the majority of networks. An exception is B-ISDN networks, which use broadband transmission.

Back To Top

: A type of data transmission in which a single medium (wire) can carry several channels at once. Cable TV, for example, uses broadband transmission. In contrast, baseband transmission allows only one signal at a time.

Most communications between computers, including the majority of local-area networks, use baseband communications. An exception is B-ISDN networks, which employ broadband transmission.

Back To Top