Glossary

A system of interconnected computers.

A network topology describes the arrangement of systems on a computer network. It defines how the computers, or nodes, within the network are arranged and connected to each other. Some common network topologies include star, ring, line, bus, and tree configurations. These topologies are defined below:

1. Star - One central note is connected to each of the other nodes on a network. Similar to a hub connected to the spokes in a wheel.
2. Ring - Each node is connected to exactly two other nodes, forming a ring. Can be visualized as a circular configuration. Requires at least three nodes.
3. Line - Nodes are arranged in a line, where most nodes are connected to two other nodes. However, the first and last node are not connected like they are in a ring.
4. Bus - Each node is connected to a central bus that runs along the entire network. All information transmitted across the bus can be received by any system in the network.
5. Tree - One "root" node connects to other nodes, which in turn connect to other nodes, forming a tree structure. Information from the root node may have to pass through other nodes to reach the end nodes.

It is helpful for a network administrator to know the pros and cons of different network topologies when putting together a network. By weighing the benefits of each type, the administrator can choose the configuration that is most efficient for the network's intended purpose.

Stands for "New Technology File System." NTFS is a file system introduced by Microsoft with Windows NT and is supported by subsequent versions of Windows, such as Windows 2000 and Windows XP. NTFS has a number of advantages over the previous file system, named FAT32 (File Allocation Table). One major advantage of NTFS is that it includes features to improve reliablity. For exmaple, the new technology file system includes fault tolerance, which automatically repairs hard drive errors without displaying error messages. It also keeps detailed transaction logs, which tracks hard drive errors. This can help prevent hard disk failures and makes it possible to recover files if the hard drive does fail.

NTFS also allows permissions (such as read, write, and execute) to be set for individual directories and files. It even supports spanning volumes, which allows directories of files to be spread across multiple hard drives. The only reason why you would not want to select NTFS when formatting your hard drive is if you like slow, outdated technology or you need to run an older operating system such as Windows 95 or MS-DOS. Of course, if you are running DOS, there is a good chance you really do like outdated technology.

When a variable has no value, it considered to be null. Having a null value is different than having a value of 0, since 0 is an actual value. However, when used in a boolean test, both null and zero result in a FALSE value. Programmers often use boolean tests to determine whether a variable has been given a value or not.