A part of a hierarchy that includes a node, its children nodes, and all the accounts and services assigned to those nodes.


The capacity to carry a quantity of information. The term can apply to telephone or computer network wiring, as well as radio frequency signals and other computing components. It has also come to mean a person's capacity for dealing with multiple projects ("I'd like to update this database, but I don't have the bandwidth."). Bandwidth is most accurately measured in cycles per second, or hertz (Hz), a unit of measure that tells the difference between the lowest and highest frequencies transmitted. But it's also common to use bits or bytes of data per second instead.


If you can read this, it's likely you're using a Web browser. A browser is a software application that acts as your entry to the World Wide Web; when you type in the address of a web site (alternately called a hypertext link or uniform resource locator -- URL), your browser makes a connection that lets you see the site on your computer monitor. It also lets you interact with a web site and navigate between sites by means of hyperlinks (the underlined words or phrases you find on many Web pages). Among the companies that produce browsers are NCSA Mosaic, Netscape, and Microsoft, as well as commercial services like America Online. While many people think of browsers as Web tools, they are also used as file managers within your computer.

Byte (B)

A byte, aka an octet or a word, usually denotes 8 bits (a bit being the smallest unit of data in computing). The computer treats a byte as a single unit. Longer sequences of 16 or 32 bits are also possible. As the number of bytes increases, other units based on the byte are used. They are loosely described in decimal terms (for example, a kilobyte is about 1,000 bytes), but their actual values are calculated as binary numbers, based on the number 2 (so a kilobyte is actually 1,024 bytes or 2 to the 10th power). The following table shows standard measures of data based on bytes:

Term Abbreviation Approximate Value Precise Binary Value
Byte B 8 bits  
Kilobyte K or KB 1,000 bytes 1,024 bytes or 2 to the 10th power
Megabyte M or MB 1 million bytes 1,048,576 bytes or 2 to the 20th power
Gigabyte G or GB 1 billion bytes 1,073,741,824 bytes or 2 to the 30th power
Terabyte TB 1 trillion bytes 1,099,511,627,776 bytes or 2 to the 40th power
Binary Group

A binary group is a kind of newsgroup -- an interactive online discussion group – that typically uses graphics and non-text media. (The other basic category of newsgroup is a text group.)

Bits Per Second (bps)

The speed at which a specified number of bits -- the smallest unit of data in computing -- is transmitted from one computer to another. (For very high numbers, bits are converted into kilobits, or units of 1,024 bits). Your modem's speed is measured in bps or kbps; if it is rated at 28,800 bps or less, it moves information rather slowly. 56 kbps is the premium modem speed.

Binary Digit (Bit)

The smallest unit of data in computing, with a value of either 0 or 1. Whenever you see a lowercase b associated with a number, it's likely to be a bit. Prefixed with "kilo" (kilobit), it means 1,024 bits; prefixed with "mega" (megabit), it refers to 1,024 x 1,024 bits. The term sometimes finds its way into data transfer speeds (such as 14.4 kilobits per second, typically shortened to 14.4 kbps).