Contribution to ontologies building using the semantic web and web mining

The volume of information that is nowadays available on the web makes the limits of the current Web clear for its users, in fact finding information and knowledge between billions of Web pages is very difficult, the Semantic web and data mining are two new fasting developing domains that will resolve this problem and the combination of this tow area will transform the web into a semantically information space in order to make sense of already-existing data designed only for human readers and then to extract the knowledge contained within the Web, many experience shows that the ontology engineering is very important to solve the problem of the interoperability between web systems by using the ontology learning from web content in order to develop method of extraction knowledge from web data and the representation of this Knowledge in a form understandable by arbitrary parties (machines, humans ...), This paper will describe the commonalities of the two areas in order to extract useful and shared Knowledge.