Flow of control in a C program

• C programs commence their execution at their main() function, execute their statements, and exit (return the flow of control) to the operating system.

• It's fairly obvious that statements need to be executed in a well-defined order, as we expect programs to always behave the same way (unless some random data directs the execution path, as in computer games, simulations, and heuristic algorithms).

• Default flow of control executes each statement in order, top-to-bottom.

• Programs that only execute from top-to-bottom are pretty boring, and we need to control their flow with a variety of conditional statements, loops, and function-calls.