The term tight and loose head come from when the props bind with the opposition. When the two teams join the tight head is stuck between two opponents head, and the loose head is only touching one head of the opposition. They are sometimes tall and usually very strong. The two players bind behind the Props, and push until told to stop. They are qiucker than the rest of the pack and must have an in depth knowledge of the game.
Flankers can often pick up the ball from the scrum and make a move toward the backs.
Once the ball is pushed back it is the 8 man's responsiblity to release it to the scrum half. He places the ball into play in the scrum, and then picks it up from the back of the pack if the team wins. This player is often the most experineced player on the team. Once he has control of the ball the Scrum half will pitch it to the Backs. These players are the fastest on the team and carry the ball forward.