Short answers, pulled from the story.
The NFL playoffs is a single-elimination tournament held after the regular season. Since the 2020 season, seven teams from each of the two conferences qualify, for a total of fourteen teams. The top seed in each conference receives a first-round bye.
The formal NFL Championship Game began in 1933, though a precursor playoff game was held in 1932 when the Chicago Bears and Portsmouth Spartans finished with identical winning percentages. The multi-round playoff tournament expanded over subsequent decades.
The longest NFL playoff overtime game ran 82 minutes and 40 seconds. Miami Dolphins kicker Garo Yepremian made a 37-yard field goal after 7:40 of the second overtime to defeat the Kansas City Chiefs 27-24 on the 25th of December 1971.
Among active franchises, the Green Bay Packers lead with 38 playoff appearances. The Dallas Cowboys and Pittsburgh Steelers each have 36. The New England Patriots hold the record for the longest consecutive playoff appearance streak at eleven seasons.
The NFL uses single elimination in every round of its postseason, unlike the NBA, NHL, and MLB, which use multi-game series. This makes the NFL postseason the only one among the four major American professional sports leagues to apply single elimination throughout.
The Oakland Raiders became the first wild-card team to win the Super Bowl, accomplishing the feat following the 1980 season. The wild-card format had expanded to two teams per conference in 1978.