HTML stands for Hypertext Markup Language. It is the primary format for the World Wide Web materials. HTML is a Document Type Definition (DTD) of Standard Generalized Markup Language (SGML).
The basic HTML document is called a "page." HTML pages are composites, often built from several files of different types (text, graphics, sounds, etc.). Pages are strung together using hypertext links.
HTTP stands for Hypertext Transport Protocol. It allows WWW clients to request and receive content from WWW servers. HTTP is optimized to make the best use of limited network and server capacity.
URL stands for Uniform Resource Locator. A URL may refer to any linkable entity, not just HTML pages (the "mailto:" URL for example). URLs are made up of four parts as follows:
| http://www.med.ufl.edu/medinfo/index.html | ||
| part | function | required? |
|---|---|---|
| http:// | the protocol or "scheme" | yes |
| www.med.ufl.edu/ | the host computer | yes |
| medinfo/ | the directory | no |
| index.html | the file | no |
URLs may be absolute or relative. An absolute URL such as "http://www.ufl.edu/" specifies all information necessary for the link. A relative URL such as "index.html" is often just a file name. The rest of the information must be filled in based on the context of the document (the current directory).
In HTML, the term "anchor" describes both the source and destination for hypertext links. For the purpose of discussion we will use the following terminology: