In computer science and programming, a continuation is an abstract representation of the control state. A continuation reifies an instance of a computational process at a given point in the process's execution. It contains information such as the process's current stack (including all data whose lifetime is within the process e.g. "local variables"), as well the process's point in the computation.
Using continuation, when a function calls another function, that is the last thing it does. An extra argument is part of every function, which will be used to pass each function's continuation. Instead of waiting for the called function to return, it puts any work it wants to do afterwards into a continuation, which it passes to the function. Essentially, this involves breaking up the code into a collection of callback functions.
