Lambda Calculus

Lambda calculus, or λ-calculus, is a formal system for function definition, function application and recursion.

In general, there are a number of different models of computation: Turing machine, Cellular automata and λ-calculus. TM is the most popular model as far as I am concerned, which was inspired by paper and pencil. Imperative languages like the pervasive C/C++, Java, etc. follow from this model. λ-calculus, proposed by Church, was inspired by mathematical functions, and has its representative languages like ML, Scheme, Lisp, etc. The last one, inspired by life forms, observes how living cells interact with neighbors, and has no popular language derived.