In my book, I highlighted the importance of the Semantic Web and its technologies. Also, I illustrated how to build the ontology with its relations and how to implement it in the semantic query. The Semantic Web is proposed as a solution to solve the problems faced by a traditional search method in the web, where the crowded of electronic documents and the number of results in billions depends on key words only. I introduced Palestine ontology, which clarifies the relations between governorates, the cities and villages in the administrative division of Palestine.