Informal Organisation refers to that organisation, which emerges on its own. It is a social structure of organisation, which is opposed to formal organisation.
Advantages of informal organisation:
(i) Faster communication: Informal organisation follows the independent channels of communication as there is no prescribed official channel. It leads to faster spread of information as well as quick feedback.
(ii) Fulfill social needs: Informál organisation satisfies social needs of the members, which is not satisfied in formal organisation. It gives them a sense of belongingness, recognition, etc.