NFL Terms; Bye Week

From Wikipedia;

In a typical use of the term "bye", the NFL rewards the two division winners from each of the two conferences which possess the best regular season record with a bye in the playoffs. This is necessitated by the current 12-team playoff structure. Eight is the next lowest power of 2, so four teams must be eliminated in the first week to get down to eight teams. The NFL is the only one of the "Big Four" North American sports leagues to offer playoff byes. (The NBA and NHL each allow 16 teams in their postseasons, while MLB allows 8, and since 8 and 16 are both powers of two, no teams receive byes.) The CFL also grants a bye to its two division winners, directly to the division finals as four other teams compete in a semi-final week.