What is the difference between check it out and check it ?Feel free to just provide example sentences.

You might hear one guy say to another guy when a pretty girl walks past them "Hey, check it out." or "Check that out." or "Check it." This is not good English and it means look at her. It is used when the peron saying it thinks the girl is attractive. (Woman also do this if the see a cute guy) ...... If you found a book at the library, you could check it out and take it home to read. ......If you caught a fish to cook for dinner you could check it for bones before cooking it. ( it is implied once you find the bones you would also remove them)