Summary of week one for the course Knowledge Engineering with Semantic Web Technologies 2015 by Harald Sack at OpenHPI.
The first week covers the basic principles of the technologies for the semantic web, especially RDF, which is one of the languages you can use for encoding information semantically. The basic principle behind the technologies are triples, which consist of subject-predicate-object. So you encode all your knowledge in that way, for example: Pluto – discovered – 1930.
One problem is that because of the syntax the expressions tend to be very long, so you can use abbreviations with namespaces like in XML or turtle, which helps you also to shorten your syntax.
Mr. Sack claims that with Semantic Web technologies you can go one step further into a web of data, because it is very easy to create data that is machine-readable. He gives a lot of examples using DBPedia. This site also provides a good interface, where you can download data in different machine-readable formats like xml or json. Example-page for Pluto.