A tighthead prop is one of the three players at the front of the scrum.
They stand on the right-hand side of the hooker.
As they take most of the impact in the scrum, a prop should have plenty of strength in their upper body.
This is the area of the body where all the power is created for the big push.
Props also tend to get stuck into tackles and often they can be found at the bottom of a ruck or the middle of a maul.