Continuations

According to Wikipedia:

"In computing, a continuation is a representation of an execution point (for example, the instruction pointer and stack frame). Many languages have constructs that allow a programmer to obtain a pointer to a continuation, and then to resume execution using the pointer at a later point in time. This technique has been used in functional programming, imperative programming, and message passing programming."

The most popular use of continuations today is in the implementation of exception handling.