The web and web technologies are developing quickly and the services are adopted at high speed. Web 2.0 and Ajax are known terms. The semantic web is regarded as being the next step in the development process and has even started being referred to as "Web 3.0". So, what is the semantic web? And how can we develop our information and our IT platform, to benefit from the advantages of this new web paradigm? The aim of this presentation is to create a concrete picture of the semantic web and its technologies.