Information theoretic foundations of cooperation dates back to van der Meulen’s three-terminal network, and Cover and El Gamal’s seminal work on the relay channel. During the past 45 years, information theory literature has provided a wide range of fundamental results establishing benefits of cooperation in various wireless scenarios. Protocols developed to facilitate cooperation among terminals result in significant improvements in communication rates and reliability. The impending 5G wireless revolution provides the perfect setting for implementing some of these protocols and reaping the potential gains of cooperation: Large number of antennas and wide bandwidth, as in millimeter wave systems, provide abundant degrees of freedom; cloud computing and cheap storage enable enhanced computing capabilities at the network edge; full-duplex radio designs allow nodes to transcend traditional duplexing limitations; and applications such as Internet of Things provide a natural setting for cooperative communication and compression. This talk provides a brief overview of the theoretical foundations of cooperative communications along with a few examples of how even simple forms of cooperation could make big impact in future 5G wireless networks.