1. Communication: Communication is the process whereby the people can transfer message from one person to another. It likes one way communication, tow way communication. For example- Mass media, lecture class, discussion etc. 

2. Yes, obviously i think communication can change the face of public health system. By mass media communication system people can aware about their health status and they can learn from each others. Communication system also help to inform about the community and this channel can help to strong the health care delivery system from far.