Differences between fork and exec?

Question

What are the differences between `fork` and `exec`?

Answer 1

`fork` and `exec` are two functions very commonly used together in systems

programming.

* `fork` makes a copy of your process

* `exec` replaces the current process with a new program

Together they can be used to run another program:

1) `fork` the current process. In the parent process, keep running the original

program ("program A"). In the child process,

2) `exec` the other program ("program B")

After this two-step dance, the end result is one process with program A and one

process with program B.