Nowadays, computation is playing an increasingly more important role in the future generation of computer and communication networks, as exemplified by the recent progress in SDN for wired networks as well as C-RAN and mobile cloud computing (MCC) for wireless networks. This article proposes a unified concept (i.e., computation diversity) to describe the impact and diverse forms of the computation resources on both wired and wireless communications. By linking the computation resources to the communication networks based on quality of service requirements, we can show how computation resources influence the networks. Moreover, by analyzing the different functionalities of computation resources in SDN, C-RAN, and MCC, we can show the diverse and flexible forms that the computation resources present in different networks. The study of computation diversity can provide guidance in future networks design as far as how to allocate the resources jointly between computation (e.g., CPU capacity) and communication (e.g., bandwidth), thereby saving system energy and improving users' experiences.