A free kick in football is any type of a kick that is performed behind restraining lines. In football kickoffs are free kicks made behind restraining lines. Free kicks are typically made after a safety is scored. The team that didn't score must either punt or place kick the ball from the 20 yard line. This is performed by one player who drops the ball and kicks it before it touches the ground.
Once it's been kicked, the opposing team can catch it and gain yards down the field. Any member of the kicker's team may also take possession of the ball, but only after it bounces once or already touched another player.
Free kicks are performed by a special teams unit member, so much of the responsibility is on him. The kicker (who is usually the shortest player on the team), should be light on his feet and skilled enough to intentionally kick the ball so it lands on a particular area of the field. However, after the ball is kicked, it is now the defense's responsibility to stop the receiving team from gaining any yards. The defense is usually spread in a zone or man to man to stop the progression of the ball down the field.