After having discussed the definition of communication, let us deal with the different types of communication. Crystal developed the following aspects of semiotics which are related to language according to its nature:

a) Auditory-vocal: speech, physiological reflexes, musical effects and voice qualities.
b) Visual: sign languages, writing codes and kinesics.
c) Tactile: Deaf and blind languages, secret codes and proxemics.
d) Olfactory and gustatory.

As CRYSTAL argued, some of these aspects have a linguistic nature, such as speech, deaf and deaf-blind sign languages and written language. The communicative use of the visual and tactile modes in their non-linguistic aspects is referred as “non-verbal communication” or body language.