Answer:

A Message is the idea or thought that senders must convey (Codification), ad receivers must convert (Decodification).

Codification - Converting thoughts into symbols and message.

Decodification - Conserving observable signals into thoughts.

For messages to be effective, there should be a similarity in terms of schema between the receiver and sender.

Schema - The field of experience of a person. The bigger the schema, the better the interpretation. Thus, there is effective communication.

Hope that helps :)