Hi Hossein,
If you go to google.com and type "define:HTML", you will get several good definitions for HTML. You can do the same with any word/abbreviation. If you type in "wiki HTML" you will get a wikipedia page for HTML at the top of your results.
From Wikipedia:
HTML: HTML, which stands for HyperText Markup Language, is the predominant markup language for web pages.
DHTML: Dynamic HTML, or DHTML, is an umbrella term for a collection of technologies used together to create interactive and animated web sites[1] by using a combination of a static markup language (such as HTML), a client-side scripting language (such as JavaScript), a presentation definition language (such as CSS), and the Document Object Model.
XHTML: XHTML (Extensible Hypertext Markup Language) is a family of XML markup languages that mirror or extend versions of the widely used Hypertext Markup Language (HTML), the language in which web pages are written.
XML: XML (Extensible Markup Language) is a set of rules for encoding documents electronically. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards.
GML: Generalized Markup Language (GML) is a set of macros that implement intent-based markup tags for the IBM text formatter, SCRIPT/VS. SCRIPT/VS is the main component of IBM's Document Composition Facility (DCF). A starter set of tags in GML is provided with the DCF product.
GML was developed in the 1960s by Charles Goldfarb, Edward Mosher and Raymond Lorie (whose surname initials were used by Goldfarb to make up the term GML).
GML simplifies the description of a document in terms of its format, organization structure, content parts and their relationship, and other properties. GML markup (or tags) describes such parts as chapters, important sections, and less important sections (by specifying heading levels), paragraphs, lists, tables, and so forth.
SGML: The Standard Generalized Markup Language (ISO 8879:1986 SGML) is an ISO-standard technology for defining generalized markup languages for documents. ISO 8879 Annex A.1 defines generalized markup:
Generalized markup is based on two novel postulates:
* Markup should describe a document's structure and other attributes, rather than specify the processing to be performed on it, as descriptive markup need be done only once, and will suffice for future processing.
* Markup should be rigorous so that the techniques available for processing rigorously-defined objects like programs and data bases, can be used for processing documents as well.
URI: In computing, a Uniform Resource Identifier (URI) is a string of characters used to identify a name or a resource on the Internet. Such identification enables interaction with representations of the resource over a network (typically the World Wide Web) using specific protocols. Schemes specifying a concrete syntax and associated protocols define each URI.
URL: In computing, a Uniform Resource Locator (URL) is a subset of the Uniform Resource Identifier (URI) that specifies where an identified resource is available and the mechanism for retrieving it. In popular usage and in many technical documents and verbal discussions it is often incorrectly used as a synonym for URI,[1] the best-known example of which is the "address" of a web page on the World Wide Web.