This paper presents taxonomy of models of computation. It includes Existential (Physical, Abstract and Cognitive), Organizational, Temporal, Representational, Domain/Data, Operational, Process-oriented and Level-based taxonomy. It is connected to more general notion of natural computation, intrinsic to physical systems, and particularly to cognitive computation in living organisms and artificial cognitive systems. Computation is often understood through the Turing machine model, in the fields of computability, computational complexity and even as a basis for the present-day computer hardware and software architectures. However, several aspects of computation, even those existing in today's applications, are left outside in this model, thus adequate models of real-time, distributed, self-organized, resource-aware, adaptive, learning computation systems are currently being developed.