Difference between revisions of "Semantic web"
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| − | add either structural/presentational (HTML) or semantic (XML) information to plain text. | + | add either structural/presentational (HTML) or semantic (XML) information to plain text. CSS and XSL are languages that instruct browsers on how to display HTML and XML pages (these are called stylesheets). Schema (often called DTDs) provide the relationships between the mark-up tags used in the document. The <Doctype> declaration at the beginning of an HTML or XHTML document points to the schema at W3. |
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Revision as of 16:14, 8 April 2011
Introduction
One difficulty with the web is its sheer size. In the early days, I navigated the Internet through a combination of errance and navigating through hierarchical Gopher menus (which by 1995 began to be supplanted by web directories like Yahoo! and AltaVista
Search engines made the web much more accessible: AltaVista (95), Infoseek, Lycos, Exicte (which could have bought Google for 750,000 in 1998), and of course Google.
Markup languages
The languages of the web, such as:
- SGML
- Standardized General Markup Language
- XML
- eXtensible Markup Language
- (x)HTML
- (eXtensible?) HyperText Markup Language
add either structural/presentational (HTML) or semantic (XML) information to plain text. CSS and XSL are languages that instruct browsers on how to display HTML and XML pages (these are called stylesheets). Schema (often called DTDs) provide the relationships between the mark-up tags used in the document. The <Doctype> declaration at the beginning of an HTML or XHTML document points to the schema at W3.
