In the Teaching - Learning process, the teaching aids constitute a key factor in the didactic process.
They favor that the two-way communication that exists between the protagonists can be established in a more affective way.
Various components are involved in this communication process, such as: information, message, channel, sender, receiver, encoding and decoding.
In communication, when the change in attitude that occurs in the subject, after interacting these components, is lasting, we say that learning has occurred.