What is the Semantic Web?

Definitions:
1. The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries. It is a collaborative effort led by W3C with participation from a large number of researchers and industrial partners. It is based on the Resource Description Framework (RDF). See also the separate FAQ for further information [1].

2. Right now the HTML+CSS is centered more on structure and presentation. Semantics is about the meaning of the information. In semantic web you use shared ontologies to establish meaning (semantic) of the object and meaning of relations between the objects. Best known ontologies are: FOAF and Dublin Core.

Typically semantics would be expressed in specialized language, such as RDF or OWL. RDF can be embedded within XHTML using eRDF or W3C's RDFa.

Less structured alternative to eRDF/RDFa are microformats. [2]

3. This is a more practical definition which I understand much more. I found it in Stackoverflow as well.

4. Real world example

5. Introduction to the Semantic web

6. Semantic web frameworks

7. Semantic web and Syntactic web resources

8. Commercial applications using Semantic web

9. Semantic web stack

10. Semantic web site

11. The Semantic Web is about two things. It is about common formats for integration and combination of data drawn from diverse sources, where on the original Web mainly concentrated on the interchange of documents. It is also about language for recording how the data relates to real world objects [3].

12. Semantic Web Standards Wiki

13. Semantic Overflow

14. Semantic Web Case Studies and Use Cases

References:

[1] Stackoverflow

[2] Stackoverflow
[3] W3C Semantic Web