The world of computers and the Internet can be confusing for those who are not familiar with the terminology in use. To help you with this we have provided this brief list of common terms.

A | B | C | D | E | F | G | H | I | J | K | L | M

N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A botnet (also known as a zombie army) is a number of Internet computers that, although their owners are unaware of it, have been set up to forward transmissions (including spam or viruses) to other computers on the Internet. Any such computer is referred to as a zombie - in effect, a computer "robot" or "bot" that serves the wishes of some master spam or virus originator.

An intangible property right in original material created by an author. Examples of copyrighted material include software, music, images, or multimedia works. Copyrighted works also include any original expression, which appears on someone's home page or is transmitted in a newsgroup or by e-mail.

A Denial of Service is a specific arrangement of data sent to a target with the specific intent of interrupting that target's Internet service. Examples of denial of services are: Winnuke, Teardrop, Land, Nestea, Smurf and Fraggle. There are new denial of service attacks created on a daily basis and the best way to protect yourself is to install all of the appropriate patches.

A firewall is a device, either a software application or hardware product, which can be configured to limit certain types of communication that can pass through it. It can be installed as a network gateway device or on a single computer. A firewall needs to be configured and told what to do - what to allow / what not to allow over the network. It is often used to help secure a computer and/or a network on the Internet so that others only have limited access to communicate with the computer or network. A firewall can also be used to help limit or control the type of activity which it will allow, even if it is not directly related to security.

A firewall works by examining each data packet it receives and processes the packet against a set of rules with which it has been configured to determine if it will allow, pass on the packet, or deny/drop, stop the packet. If it stops the packet, it will not reach its destination and that communication attempt will be stopped. A firewall is a general term and originally firewalls were designed specifically as a device to limit types of communication over a network. Firewalls are now being expanded to filter activity based not only on types of communication, but if on a single computer, the applications that can use the Internet and in some cases, the content that can be sent over the Internet from that computer.

A firewall, while often a helpful resource in securing a computer or network, should not be considered a security solution. A firewall is often considered to be only part of a solution, as it alone cannot guarantee the appropriate use or security of the network or computer it is running on.

An IP address is a unique number that is assigned to your computer that allows it to communicate over the Internet. An IP, Internet Protocol, address is much like a telephone number. Computers only communicate via an IP address; however, most people type in domain names of computers to which they want to connect. There is a unique service that translates these names into IP addresses, and vice versa. This is called DNS, which stands for Domain Name Service. This is much like a telephone's caller ID. Telephones only work via a unique identification number, a telephone number, but you can often program your phone with speed dial by name and when people call you, if you have caller ID, you can see their name as well. With any Internet connection, you must have an IP address that allows you to communicate with other computers just like you must have a telephone number to talk with other people. No one else on the Internet will have the same IP address as you. Currently, using the IP version 4 protocol, an IP address looks like this: "#.#.#.#" - each of the 4 numbers that makeup an IP address can be anywhere from 0-255. So, mathematically, there are 4,294,967,296 IP addresses that could be used. However, many of these IP addresses are not usable on the Internet, so the number is actually somewhat lower. However, there are still somewhere around 4 billion IP addresses with the current system.

More information on IP addresses can be found at http://whatis.techtarget.com/definition/0,289893,sid9_gci212381,00.html

Internet Relay Chat (IRC) is a system for chatting that involves a set of rules and conventions and client/server software. IRC networks such as the Undernet provide servers and help you download an IRC client to your PC.

An IRC Bot is an automated program that controls or enhances your participation during an IRC session. A bot can be used for malicious purposes such as flooding, i.e. sending a great deal of data at someone for the purpose of denying them service to the chat room.

MP3 (MPEG-1 Audio Layer-3) is a standard technology and format for compressing a sound sequence into a very small file (about one-twelfth the size of the original file) while preserving the original level of sound quality when it is played.

Netiquette is etiquette on the Internet. Since the Internet changes rapidly, its netiquette does too, but it's still usually based on the Golden Rule. The need for a sense of netiquette arises mostly when sending or distributing e-mail, posting on Usenet groups, or chatting. To some extent, the practice of netiquette depends on understanding how e-mail, the Usenet, chatting, or other aspects of the Internet actually work or are practiced.

A newsgroup is a discussion about a particular subject consisting of notes written to a central Internet site and redistributed through Usenet, a worldwide network of news discussion groups.

An open proxy is a server that acts as an open relay but uses ports other than the normal SMTP port 25. Open proxies provide surrogate (proxy) communication ability to other servers or PC's through ports not reserved for normal use. There are many viruses and Trojans that can be used to install open proxy software on an unsuspecting user's computer. This is the most common usage of a proxy on a cable modem network. Spammers regularly use these types of servers to disguise the true origin of their unwanted e-mail. In recent months spammers have even joined forces with virus writers to develop more robust Trojans and viruses to be used solely for the purpose of sending spam. If you have received an notification (vie e-mail or postal mail) from Insight's Policy Enforcement Team about spam e-mail then it's likely that spammers have indeed located and exploited your insecure PC for this very reason.

1. On computer and telecommunication devices, a port (noun) is generally a specific place for being physically connected to some other device, usually with a socket and plug of some kind. Typically, a personal computer is provided with one or more serial ports and usually one parallel port. The serial port supports sequential, one bit-at-a-time transmission to peripheral devices such as scanners and the parallel port supports multiple-bit-at-a-time transmission to devices such as printers.

2. In programming, a port (noun) is a "logical connection place" and specifically, using the Internet's protocol, TCP/IP, the way a client program specifies a particular server program on a computer in a network. Higher-level applications that use TCP/IP such as the Web protocol, Hypertext Transfer Protocol, have ports with pre-assigned numbers. These are known as "well-known ports" that have been assigned by the Internet Assigned Numbers Authority (Internet Assigned Numbers Authority). Other application processes are given port numbers dynamically for each connection. When a service (server program) is initially started, it is said to bind to its designated port number. As any client program wants to use that server, it also must request to bind to the designated port number.

Port numbers are from 0 to 65536. Ports 0 to 1024 are reserved for use by certain privileged services. For the HTTP service, port 80 is defined as a default and it does not have to be specified in the Uniform Resource Locator (Uniform Resource Locator).

3. In programming, to port (verb) is to move an application program from an operating system environment in which it was developed to another operating system environment so it can be run there. Porting implies some work, but not nearly as much as redeveloping the program in the new environment. Open standard programming interface (such as those specified in X/Open's 1170 C language specification and Sun Microsystem's Java programming language) minimize or eliminate the work required to port a program. Also see portability.

A port scan is a series of messages sent by someone attempting to break into a computer to learn which computer network services, each associated with a "well-known" port number, the computer provides. Port scanning, a favorite approach of computer cracker, gives the assailant an idea where to probe for weaknesses. Essentially, a port scan consists of sending a message to each port, one at a time. The kind of response received indicates whether the port is used and can therefore be probed for weakness.

Types of port scans include:

• Vanilla - An attempt to connect to all ports (there are 65,536)
• Strobe - An attempt to connect to only selected ports (typically, under 20)
• Stealth scan - Several techniques for scanning that attempt to prevent the request for connection being logged
• FTP Bounce Scan - Attempts that are directed through an File Transfer Protocol server to disguise the cracker's location
• Fragmented Packets - Scans by sending packet fragments that can get through simple packet filters in a firewall
• UDP - Scans for open User Datagram Protocol ports
• Sweep - Scans the same port on a number of computers

The name of the result and the process for creating a standard on the Internet. New standards are proposed and published on line, as a "Request For Comments". The Internet Engineering Task Force is a consensus-building body that facilitates discussion, and eventually a new standard is established, but the reference number/name for the standard retains the acronym "RFC", e.g. the official standard for e-mail is RFC 822.

A sniffer can be used illegitimately to capture data being transmitted on a network. A network router reads every packet of data passed to it, determining whether it is intended for a destination within the router's own network or whether it should be passed further along the Internet. A router with a sniffer, however, may be able to read the data in the packet as well as the source and destination addresses.

A spider is a program that visits Web sites and reads their pages and other information in order to create entries for a search engine index. The major search engines on the Web all have such a program, which is also known as a "crawler" or a "bot." Spiders are typically programmed to visit sites that have been submitted by their owners as new or updated.

In computers, a Trojan horse is a program in which malicious or harmful code is contained inside apparently harmless programming or data in such a way that it can get control and do its chosen form of damage, such as ruining the file allocation table on your hard disk. In one celebrated case, a Trojan horse was a program that was supposed to find and destroy computer viruses. A Trojan horse can be considered a virus if it is widely redistributed.

A virus is a piece of programming code usually disguised as something else that causes some unexpected and, for the victim, usually undesirable event and which is often designed so that it is automatically spread to other computer users. Viruses can be transmitted by sending them as attachments to an e-mail note, by downloading infected programming from other sites, or be present on a diskette or CD. The source of the e-mail note, downloaded file, or diskette you've received is often unaware of the virus. Some viruses wreak their effect as soon as their code is executed; other viruses lie dormant until circumstances cause their code to be executed by the computer. Some viruses are playful in intent and effect ("Happy Birthday, Ludwig!") and some can be quite harmful, erasing data or causing your hard disk to require reformatting.