Potential modes of interaction among nodes in wireless networks have become increasingly complex, as more flexible network architectures emerge, as the processing power of individual nodes increases, and as greater efficiencies in the use of radio resources are needed. These node interactions can be either competitive or cooperative. Examples of competitive behavior among wireless nodes arise in areas such as cognitive radio, secure transmission, and in game theoretic modeling. Examples of cooperative behavior arise in network coding, cooperative transmission and relaying, multi-hop transmission and coalition games, collaborative beam-forming and collaborative inference. This talk illuminates this issue of node interaction through discussion of a number of specific examples.