What is the purpose of fork()?

Question

In many programs and man pages of Linux, I have seen code using fork(). Why do we need to use fork() and what is its purpose?

Answer 1

Fork() system call use to create a child process. It is exact duplicate of parent process. Fork copies stack section, heap section, data section, environment variable, command line arguments from parent.

refer: http://man7.org/linux/man-pages/man2/fork.2.html