What is Which of the following is not a 2 way communication – and explain in detail?
Communication 

Communication is a process of transferring information from one source to another.
There are following types of communication :-

1. One-way communication (Didactic method)

One way communication is one in which information is always transferred in only one preassigned direction, i.e. from communicator to the audience.
Example - Lectures, demonstration, mass media communication (TV, radio, internet).

2. Two-way communication (Socratic method)

It is method of communication in which both the communicator and the audience take part and the information is transferred in both direction.
Examples →Group discussion, Panel discussion, symposium, workshop, conferences.
Verbal communication → communication by words of mouth.
Non-verbal communication → communication without words, by whole range of bodily movements, postures, gestures, facial expressions (e.g. smiling, frown).
Formal and informal education
Follows lines of authority → Formal communication.
From channels that fall outside the formal communication → informal (grape-vine) communication.
Visual communication → charts, graphs, tables etc.
Telecommunication and internet → Telecommunication is the process of communication over distance using electromagnetic instruments designed for the purpose.
Examples → Radio, TV and internet.