The beauty of fantasy football—well, one of them—is that games come in many flavors. For more casual fans and weekend practitioners, there are daily fantasy sports (DFS) games. For the traditional fantasy enthusiast, there are season-long leagues. For the diehard fantasy fans, there are keeper and dynasty leagues.
Keeper leagues don't quite require an all-in commitment, as generally only one or two players are retained from year to year. However, there is a strategy involved when considering whom to keep and when to redraft.
Dynasty leagues are for the fantasy aficionado. Championship rosters are built over years, not weeks or months, and suffering through losing campaigns is generally part of the equation.