This paper gives an overview of some models of computation which have proved successful in laying a foundation for a general theory of parallel computation. We present three models of parallel computation, namely boolean and arithmetic circuit families, and Parallel Random Access Machines. They represent different viewpoints on parallel computing: boolean circuit families are useful for in-depth theoretical studies on the power and limitations of parallel computers; Parallel Random Access Machines are the most general vehicle for designing highly parallel algorithms; arithmetic circuit families are an important tool for undertaking studies related to one of the most active areas in parallel computing, i.e. parallel algebraic complexity