How are the teams which qualify for the National Football League Playoffs determined?

The 32 teams that comprise the National Football League are organized by two conferences, the American and National, with four divisions of four teams in each conference.  Each year the team with the best record in their division automatically qualifies for the playoffs.  In addition, the three remaining teams with the best records in each conference also qualify and are designated as "wildcards".  Tiebreakers are used to determine who makes the playoffs in scenarios where two or more teams finish with the same number of wins.  Tiebreakers can include head-to-head competition, record in conference, and record against common opponents.