Skills

Similar to the way that football scoring is unique, so are the skills to play.  Most unique is the fact that each position on the field has a specific purpose.  Although many of the skills are used in various positions, some of the positions are so unique, that one or two weak (or injured) players can cripple an entire team.
       The skills to play include passing the ball, catching the ball, and running with the ball, all while avoiding being tackled.  Every defensive player must know how to tackle; as their entire objective is to find the player with the ball and tackle him.  There are rules about tackling, to promote player safety, but for the most part, just grab, smash and pull down hard.  Anything to get the ball carrier on the ground.
       Blocking is the art of of protecting the ball carrier from the tacklers.  sounds pretty simple, but when only on man has the ball, that means 10 other men are working in unison to protect and direct him.  All the while, 11 defensive players are all charging toward the ball carrier.  There are plenty of rules about how to block properly and safely, but in order to watch the game of football and understand it, know this:  Any blocking must be performed without actually grabbing or "Holding" the other team's player.  Basically, close your fist, and then try to stop the guy from getting around you and tackling your teammate.  Makes for some all out war on the field.
       So far, we've spoken a lot about elements that pertain to offense and defense.  Because the positions on offense and defense are so different, most players will only be a part of one unit.  Very rarely do you find an athlete that plays offense and defense for his team at the pro level.  However, in this wonderful game of football, there is another unit that plays an important part.  It's called the Special Teams.
       The Special Teams unit is usually a mixture of offensive and defensive players that are on "extra duty" if you will.  The Special Teams unit will be on the field for all kickoffs, punts, field goals and various trick plays.  Having a good Special Teams unit rarely makes headlines, but having a bad one will cost you many games.