This document provides an overview of agricultural extension and communication. It defines agricultural extension as the application of scientific research to improve farmer education and boost productivity. It discusses major problems in agriculture like rising population and need to increase food production. It then outlines the history of extension, from its origins in England in the 1800s to the establishment of cooperative extension services in the US in 1914. It also summarizes the development of extension in the Philippines under different presidential administrations. Finally, it covers the roles of extension workers and basic principles of extension practice like the importance of communication, working with rural people, and accountability to clientele.