What does a Flanker do in Rugby? ?

a flanker flanks at the side of the scrum.. hence the name. They are generally great athletes and good tacklers and fast runners. They are responsible for being fast on defence if the opposition wins the ball

Quite simply put...the ball.
The ball & the flanker should be magnets.if u r a flanker, u want the ball or to secure the ball. Your job is to steal it & protect it.
However, these days it is changing...a blindside flanker (6) is now seen as a line out jumping option & has more of a defensive role around the ruck.
The open side (7) still has that.''gotta get the ball mentality'' & is more of an offensive player than defensive.
And (8) has a nice free role...basically to support his back line in defense & support his forwards in offense.

As a general rule for beginners:

- be first to almost every breakdown
- be first onto any loose balls
- sweep the defensive line.
- put pressure on opposition scrum half/fly half

Basically, between them, the back row (6, 7 & 8) should be responsible for a lot of things, so ur game will vary depending on how the others like to play.

For example, of the list above: If ur fellow back row players like to sweep the line in defence, u should concentrate on putting pressure on the scrum half, fly half, & the attacking backs so u can hopefully disrupt them.

In general, they should be first to a majority of break downs, & always be around when there is a chance of winning the ball. (i.e. picking it up when someone goes to ground & a ruck hasnt formed, ripping it off someone who has shown the ball too much in contact)

A lot of responsibility is also held for cleaning up the ball. As flankers tend not to commit to rucks when they r not the first there, & r rarely used in line outs, if the ball finds its way out somewhere, & is bobbling around on the floor, it generally falls to them to react, gather it, & clean it up!!