A program that automatically fetches Web pages. Spiders are used to feed pages to search engines. It's called a spider because it crawls over the Web. Another term for these programs is webcrawler.

Because most Web pages contain links to other pages, a spider can start almost anywhere. As soon as it sees a link to another page, it goes off and fetches it. Large search engines, like Alta Vista, have many spiders working in parallel.

A formula or set of steps for solving a particular problem. To be an algorithm, a set of rules must be unambiguous and have a clear stopping point. Algorithms can be expressed in any language, from natural languages like English or French to programming languages like FORTRAN.

We use algorithms every day. For example, a recipe for baking a cake is an algorithm. Most programs, with the exception of some artificial intelligence applications, consist of algorithms. Inventing elegant algorithms -- algorithms that are simple and require the fewest steps possible -- is one of the principal challenges in programming.

Abbreviation of Uniform Resource Locator, the global address of documents and other resources on the World Wide Web.

The first part of the address indicates what protocol to use, and the second part specifies the IP address or the domain name where the resource is located.

A special HTML tag that provides information about a Web page. Unlike normal HTML tags, meta tags do not affect how the page is displayed. Instead, they provide information such as who created the page, how often it is updated, what the page is about, and which keywords represent the page's content. Many search engines use this information when building their indices.

(1) Often abbreviated DB. A collection of information organized in such a way that a computer program can quickly select desired pieces of data. You can think of a database as an electronic filing system.

Traditional databases are organized by fields, records, and files. A field is a single piece of information; a record is one complete set of fields; and a file is a collection of records. For example, a telephone book is analogous to a file. It contains a list of records, each of which consists of three fields: name, address, and telephone number.

An alternative concept in database design is known as Hypertext. In a Hypertext database, any object, whether it be a piece of text, a picture, or a film, can be linked to any other object. Hypertext databases are particularly useful for organizing large amounts of disparate information, but they are not designed for numerical analysis.

To access information from a database, you need a database management system (DBMS). This is a collection of programs that enables you to enter, organize, and select data in a database.

(2) Increasingly, the term database is used as shorthand for database management system.

A SEO technique used by Web designers to overload keywords onto a Web page so that search engines will read the page as being relevant in a Web search. Because search engines scan Web pages for the words that are entered into the search criteria by the user, the more times a keyword appears on the Web page the more relevancy the search engine will assign to the page in the search results (this is only one way that search engines determine relevancy, however.) Search engines often penalize a site if the engine discovers keyword stuffing, as this practice is considered poor netiquette, and some search engines will even ban the offending Web pages from their search results.

There are several methods of keyword stuffing. One way is to insert repeating keywords within the input type="hidden" field meta tag or the keyword tag so that the keywords are not seen by the user but are scanned by the search engine. Another way is to make text in the body of the Web page invisible text, or hidden text, by making the text the same colour as the page’s background, rendering the text invisible to the user unless the user highlights the text. This method is called invisible keyword stuffing.

Keyword stuffing also is referred to as keyword loading and spamdexing.