SPARQL
What is SPARQL
SPARQL is a query language for semantic databases using the Resource Description Framework (RDF) format
Tutorial
There are quite a few tutorials out there for SPARQL e.g.
This tutorial is for people which are new to semantic concepts but would like to use an example with a fair amount of data but not too much of complexity in the structure of the data.
Semantic Concepts
Personally I learned Semantic Concepts using Semantic MediaWiki see
Triples
A semantic statement has the form
<subject> <predicate> <object>
e.g.
Dubai is-located-in AE
The natural language statement "Dubai is located in United Arab Emirates" is purposely slightly modified to a more "computer-ready" form. The predicate has been written as is-located-in to make it a proper Identifier. And the country-name "United Arab Emirates" has been replaced by its two letter United Nations Location Code AE.