Function
Modules in ‘C’ are functions. A function is a self contained block of statements that perform a specific task of some king. Every ‘C’ program is a combination of one or more functions.
Main is also a function with a reserved name, main()
A common analogy for the concept of functions is the hierarchical form of management.
A boss (the calling function or caller) asks a worker (the called function) to perform a task and report back, when the task is done.
The worker may call for other worker functions, and the boss will be unaware of this.
Note, that worker 1 acts as a boss function to worker 4 and worker 5.
Relationships among functions may differ from the hierarchical structure shown in the above figure.
Similarly, the main function communicates with several worker functions in a hierarchical manner.
For example, a function needing to display information on the screen, calls the worker function ‘printf’ to perform the task, then printf displays the information and reports back or returns to the calling function, when its task is completed.
