This paper introduces a domain ontology to describe learning material that compose a course, capable of providing adaptive e-learning environments and reusable educational resources. Two characteristics have been considered to describe each resource: (1) the most appropriate learning style and, (2) the most satisfactory hardware and software features of the used device. Basically, we have adopted the Felder-Silverman Learning Style Model for the learning styles and we have based in the FIPA Device Ontology for the description of the devices. Also, some elements from the IEEE LOM Standard have been chosen to describe other metadata of the learning resources. The ontology has been developed under OWL language, the last standard language by the W3C to represent ontologies in the Web.