What is return; (without value) means?

What is return; (without value) means?

References

Reference NO 1

http://stackoverflow.com/questions/15194243/what-is-return-without-value-means

Reference NO 2

http://stackoverflow.com/questions/9583721/c-return-without-value

Reference NO 3

http://en.wikipedia.org/wiki/Return_statement

Reference NO 4

http://cboard.cprogramming.com/c-programming/92562-no-return-value.html

Reference NO 5

http://www.c4learn.com/function-with-no-arguments-and-no.html

Reference NO 6

http://www.macs.hw.ac.uk/~pjbk/pathways/cpp1/node161.html

Reference NO 7

http://www.cplusplus.com/forum/beginner/24461/

Reference NO 8

http://php.net/manual/en/functions.returning-values.php