In recent years, networking and collaboration have become increasingly popular in education. However, there is at present a lack of attention to the theoretical basis of networking, which could illuminate when and when not to network and under what conditions networks are likely to be successful. In this paper, we will attempt to sketch the theoretical background to networking drawing on work in sociology, psychology, and business studies and looking at 4 main theoretical frameworks: constructivism, social capital theory, Durkheimian network theory, and the concept of New Social Movements. We will also explore differences between networks on a number of factors such as goals, activities, density, spread, and power relations. (Contains 9 tables.)