Control is the term used to describe who can use what card on the field. Cards usually remain under the control of their respective owners, but there are some cards that can make an exception to this rule.
Cards such as "monsters owned by one's opponent.", " " and " " allow one to take control of
When a monster switches control to you, place it on your side of the field. It is returned to the original owner's Graveyard when sent to the Graveyard in any way.