Basic Rugby Positions
Hooker: He attempts to hook the ball, with his foot, back to his forwards in the scrum. He is usually short, light and quick
footed.
Prop Forwards: They support or prop the Hooker, keep the ball in the tunnel and prevent the scum from collapsing. They are
usually heavy with strong shoulders and neck.
Lock Forwards: The lock the front row together and drive the scrum over the ball. They are usually tall with very strong legs.
No. 8 Forward: He locks the scrum together and insures the proper exit of the ball from the scrum. He is usually very fast with strong arms and chest.
Flank Forwards: The attack the opposing backs and prevent cutbacks. They are usually fast and hard hitters.
Scrum Half: He delivers the ball into the scrum and gets the ballot his backs when it is out of the scrum. He usually has excellent ball control with his hands.
Fly Half/Standoff: This player determined the path of the ball downfield, constantly keeping the opposition off guard. He is usually a good kicker, passer and tackler.
Center ¾ Backs: They assure the quick delivery of the ball to the wing and pop kick to relieve defensive pressure. They are usually good passers, tacklers and kickers.
Wingbacks: They are runners. They should be able to dodge and outrun the opposing backs and kick when in trouble. They are usually extremely fast and excellent runners and tacklers.
Fullback: He is the last line of defense. He usually uses kicking as a defensive maneuver. He often starts counter offensives when the opposition kick the ball to try get territorial advantage. He must be an excellent kicker, runner, tackler and strategist.
Here's a quick video about the forward positions
Here's a quick video about the back positions