F0 // There will be 1 child process created by first fork
F1 F1 // There will be 2 child processes created by second fork
/ \ / \
F2 F2 F2 F2 // There will be 4 child processes created by third fork
/ \ / \ / \ / \
............... // and so on
If we sum all levels of above tree for i = 0 to n-1, we get 2n - 1. So there will be 2n – 1 child processes. On the other hand, the total number of process
created are (number of child processes)+1.
Note:The maximum number of process is 2n and may vary due to fork failures.Also see this post for more details.