computation

Computation

The mechanical process of transforming input to output via fixed rules.

An algorithm is an abstract description of a computation, while a program is a concrete implementation of that algorithm in a specific model of computation. The computation is the actual execution of that program on input data.

Model of computation

A formal framework specifying what computation means.

It answers:
What constitutes a valid program?
What are the rules of execution?
What does it mean for something to be computable?

Examples: lambda calculus, turing machine.