How is it possible for fork() to return two values?

Question

Since a function in C returns only one value, all the time, how can fork(), which is also a function, return two values?

Answer 1

The fork function returns 0 to the child process that was created and returns the childs ID to the parent process.

The two seperate processes are each returned a single value.

So think of it more as one return being called on each thread process.