An Overview of Ontologies

Ontologies emerged in Artificial Intelligence as an alternative to represent knowledge. Nowadays they are a topic of interest in diverse research areas and their usefulness can be perceived in a great number of applications. This paper is aimed to answer the kind of questions a reader could elaborate to acquire a general understanding of ontologies. To achieve this goal, it presents some definitions of ontologies and it distinguishes their main characteristics. Important aspects to build an ontology are mentioned followed by some applications briefly described. Tools and languages to support their management are included as well as some excerpts of relevant research projects.