In C return is a keyword while exit() is a Standard library function.
exit() accepts as argument a value of type int while return can
supplied an expression yielding a value of any legal type. exit()
causes termination of the program while return merely returns control
to the function's caller. A special case is a return in main() which is
roughly equivalent to an exit() call. exit() calls the functions
registered with atexit() while for return this is only true when in
main().
Use exit() when you want to terminate normally from anywhere in the
program. Use return for returning control to the function's caller.
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