This glossary has been created by our whitepaper research team members. The terminology here consists of terms that they feel would be of value to you as you learn more about aligning online activity with your current online usage policies.
The terms are listed in alphabetical order and have no associated importance based on their order.
Acceptable Use Policy, also knows as ToS (Terms of Service). A contract which specifies what a subscriber can and cannot do while using an Internet Service Provider's services.
A Trojan horse exploit toolkit developed by Cult of the Dead Cow. Allows the intruder to monitor and tamper with Windows 95 or Windows 98 systems. Easily sent via e-mail, this Trojan allows the hacker to view and modify any files on the hacked computer.
The amount of data that can be transmitted in a fixed amount of time. For digital devices, the bandwidth is usually expressed in bits per second(bps) or bytes per second. For analog devices, the bandwidth is expressed in cycles per second, or Hertz (Hz).
To mark a document or a specific place in a document for later retrieval. Nearly all Web browsers support a bookmarking feature that lets you save the address (URL) of a Web page so that you can easily re-visit the page at a later time.
Pronounced cash, a special high-speed storage mechanism. It can be either a reserved section of main memory or an independent high-speed storage device. Two types of caching are commonly used in personal computers: memory caching and disk caching. A memory cache, sometimes called a cache store or RAM cache, is a portion of memory made of high-speed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory. Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM.
Disk caching works under the same principle as memory caching, but instead of using high-speed SRAM, a disk cache uses conventional main memory. The most recently accessed data from the disk (as well as adjacent sectors) is stored in a memory buffer. When a program needs to access data from the disk, it first checks the disk cache to see if the data is there. Disk caching can dramatically improve the performance of applications, because accessing a byte of data in RAM can be thousands of times faster than accessing a byte on a hard disk.
The client part of a client-server architecture. Typically, a client is an application that runs on a personal computer or workstation and relies on a server to perform some operations. For example, an e-mail client is an application that enables you to send and receive e-mail.
A message given to a Web browser by a Web server. The browser stores the message in a text file called cookie.txt. The message is then sent back to the server each time the browser requests a page from the server.
The main purpose of cookies is to identify users and possibly prepare customized Web pages for them. When you enter a Web site using cookies, you may be asked to fill out a form providing such information as your name and interests. This information is packaged into a cookie and sent to your Web browser that stores it for later use. The next time you go to the same Web site, your browser will send the cookie to the Web server. The server can use this information to present you with custom Web pages. So, for example, instead of seeing just a generic welcome page you might see a welcome page with your name on it.
Distinct pieces of information, usually formatted in a special way. All software is divided into two general categories: data and programs. Programs are collections of instructions for manipulating data.
Data can exist in a variety of forms -- as numbers or text on pieces of paper, as bits and bytes stored in electronic memory, or as facts stored in a person's mind. DMCA: Digital Millenium Copyright Act. Implements two global treaties that protect creative works in the digital era. Clarifies the rights of copyright holders and the responsibilities of online service providers to protect against piracy.
Denial of Service attack. A type of exploit designed to bring a network to its knees by flooding it with useless traffic. Ping of Death and Teardrop are two known DoS attacks which take advantage of limitations to the TCP⁄IP protocol. For all known DoS attacks, there are software patches available to fix the problem and limit the damage.
A local area network protocol developed by Xerox Corp. in 1976.
Any tool, application, or code written to take advantage of limitations in a protocol or operating system that would allow one to disrupt the integrity of service(es) the protocol or OS was intended to perform.
A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
File Transfer Protocol. A manner of obtaining files over the Internet. The way you download updates for your Web browser, probably.
Internet Control Message Protocol. An extension of Internet Protocol which supports packets containing error, control and informational messages.
As in "I seek you". A free and popular client⁄server chat application.
Instant Messenger. Another free and popular client⁄server chat application sponsored by America On Line.
Internet Protocol. One of a suite of protocols used to connect hosts on the Internet. It specifies the format of packets and their addressing scheme.
Internet Service Provider. An organization or entity that makes Web services available to end users. Most colleges and universities function as ISPs for their faculty, staff and students.
A network based on TCP⁄IP protocols (an internet) belonging to an organization, usually a corporation, accessible only by the organization's members, employees, or others with authorization. An intranet's Web sites look and act just like any other Web sites, but the firewall surrounding an intranet fends off unauthorized access.
Like the Internet itself, intranets are used to share information. Secure intranets are now the fastest-growing segment of the Internet because they are much less expensive to build and manage than private networks based on proprietary protocols.
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 zero to 255. For example, 184.108.40.206 could be an IP address.
Within an isolated network, you can assign IP addresses at random as long as each one is unique. However, connecting a private network to the Internet requires using registered IP addresses (called Internet addresses) to avoid duplicates.
Java is a general purpose programming language with a number of features that make the language well suited for use on the World Wide Web. Java source code files (files with a .java extension) are compiled into a format called bytecode (files with a .class extension), which can then be executed by a Java interpreter. Compiled Java code can run on most computers because Java interpreters and runtime environments, known as Java Virtual Machines (VMs), exist for most operating systems, including UNIX, the Macintosh OS, and Windows. Bytecode can also be converted directly into machine language instructions by a just-in-time compiler (JIT).
A free and portable operating system modeled on the UNIX operating system. Simple to configure and portable between machines, it also has many bugs and exploits.
Another client⁄server chat application being sponsored by Microsoft.
File extension for MPEG, audio layer 3. A compression technology that shrinks CD-audio by 12x without sacrificing sound quality. Allows audio files to be easily transferred across the Internet.
A remote administration (i.e. hacker exploit) tool that works like BackOrifice, with the added functionality of working with Windows NT machines. Allows a hacker to access data and gain some control over Windows functions.
A group of two or more computer systems linked together. There are many types of computer networks, including:
* local-area networks (LANs) : The computers are geographically close together (that is, in the same building).
* wide-area networks (WANs) : The computers are farther apart and are connected by telephone lines or radio waves.
An online discussion group organized by topic⁄interest. Newsreaders (built into browsers like Microsoft Internet Explorer and Netscape Navigator) are required to read and post messages.
Network news transfer protocol. A protocol used to post, distribute, and retrieve news messages.
The most important program that runs on a computer. Every general-purpose computer must have an operating system to run other programs. Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers.
Packet Internet Groper. A utility used to determine whether a specific IP address is accessible.
An interface on a computer to which you can connect a device. In TCP⁄IP and UDP networks, an endpoint to a logical connection. The port number identifies what type of port it is (e.g. port 80 is used for http traffic).
Network professional(s) who manage the electronic mail for a given domain.
An agreed-upon format for transmitting data between two devices. The protocol determines the following:
· the type of error checking to be used
There are a variety of standard protocols from which programmers can choose. Each has particular advantages and disadvantages; for example, some are simpler than others, some are more reliable, and some are faster.
From a user's point of view, the only interesting aspect about protocols is that your computer or device must support the right ones if you want to communicate with other computers. The protocol can be implemented either in hardware or in software.
· data compression method, if any
· how the sending device will indicate that it has finished sending a message
· how the receiving device will indicate that it has received a message
A server that sits between a client application, such as a Web browser, and a real server. It intercepts all requests to the real server to see if it can fulfill the requests itself. If not, it forwards the request to the real server.