The next wave of web trends portends what many term web 3.0 or the "semantic web". But what is it exact;y and what does it mean ? Well not everyone is certain - even the experts. Different people think it means different things. Generally, semantic web technologies focus on processing metadata. The metadata is processed using ontologies. Ontologies define the relationships, the rules and the logic that apply to the metadata.
Using Semantic Web technologies, metadata is given a well-defined meaning enabling computers to process higher-level “knowledge” about the data.
For example, the statement "John is the son of William" if defined in a genealogical ontology would allow the system to infer an additional relationship - William is the father of John. what results is an increasing ability for machine to turn content into meaning and thus being able to perform for the user functions that are more highly tuned to the needs of users, based on their behaviors.
For those still having trouble with the Semantic Web concept, think of the world's databases turned inside out and exposed for all others to explore, extend and remix: the hooks and loops of a loosely connected "semantic" velcro, thus enabling the "machine" to deliver experience better and more functionally for the user. It means figuring out how to make all that data more easy to understand and interpret - unlocking power and relevance of the web to a higher level with good and potentially terrifying implications.
For expert interpretation of web 3.0 trends please see Sir Tim Berner Lee's conversation on the semantic web below: