The Women's National Invitation Tournament is the counterpart to the Men's NIT and is played in both a preseason and postseason iteration. The preseason tournament started in 1994 usually lasting about 2 weeks during the November portion of the non-league schedule. The postseason tournament was first played in 1998, a few years later.
The preseason tournament includes a 16 team field. They are all guaranteed to play at least 3 games during the tournament meaning there are loser brackets that play out for the lower place finishes below 1st and 2nd. The postseason tournament is a single elimination style tournament that has a 64 team field. The games are all played at the school who has the higher seed within the bracket, no regional games are played in this tournament. The seeding is 1-16 in the four separate regions of the bracket.
The preseason tournament involves a very subjective selection process with the best teams according to multiple factors being invited to play. The postseason tournament however has a lot more structure. Half of the field, or 32 teams, are automatic berths of the top available team that did not make the NCAA Tournament field across all 32 conferences in women's basketball. So, one team per conference is accepted into the field. The other 32 schools are selected at-large with the best teams available receiving invitations. The only stipulation is that every at-large team must be at least .500 in the regular season.
The Connecticut Women's Basketball program is one of the most successful programs in the history of college athletics and holds the most preseason WNIT wins at 3, none since 2005. Other schools that have multiple preseason tournament victories include Louisville, Louisiana Tech, Notre Dame, North Carolina, Baylor, and Purdue. No team has won the postseason WNIT more than once since its inception but the past 3 winners include Arizona, Indiana, and Michigan.