This meaning refers informally to male people.
The guys are playing football outside.
Three guys helped carry the table.
This common informal use addresses or describes a mixed group of people, though preferences about the term vary.
Are you guys ready to leave?
Thanks, guys, for all your help.
This is the third-person singular form of guy and means stabilizing an object with tensioned ropes or wires.
The crew guys the mast with steel cables.
The system guys the tower against strong winds.
