The present paper aims to present the main theoretical and practical aspects of what ontology and knowledge bases mean, having the role of providing as precise information as possible. Ontologies are considered to be a vocabulary of concepts, and the purpose of this "vocabulary" is to ensure a semantically based level of knowledge based on semantics in order to define semantic ideas and relationships between them. Starting from this concept, it should be noted the idea of using the knowledge by a system that groups them into a knowledge base, which means representing the experience accumulated by human specialists in solving the problems in the field in question. This knowledge refers strictly to an ontology of the domain, to the rules used, but also to the restrictions that minimize the search space.