Communication is right at the heart of Extension profession and farmers' informal way of communication constitutes an important part of any farming system. The book proposes the theoretical bases of farmers' communication system at the grassroots. The theories on communication and communication networks have also been discussed to give farmers' communication system a theoretical grounding. The book links farmer-to-farmer communication system with the sustainable rural livelihood framework and shows the possible information and communication support needed to sustain rural livelihoods.