(CNN)Here's some background information about the NCAA Men's Basketball Tournament.
March 17-April 6, 2015 - The NCAA Men's Basketball Tournament takes place.
April 4, 2015 - The NCAA Final Four is hosted in Indianapolis, Indiana, at Lucas Oil Stadium. No. 1 seed Wisconsin defeats No. 1 overall seed Kentucky 71-64; No. 1 seed Duke defeats No. 7 seed Michigan State 81-61.
April 6, 2015 - The 2015 NCAA men's basketball championship is played in Indianapolis, Indiana. Duke defeats Wisconsin 68-63, for its fifth national title.
68 teams are invited to compete.
- 31 teams receive automatic bids by winning their conference tournaments.
- The Ivy League regular season champion receives an automatic bid.
- 36 teams receive an at-large bid from the NCAA Selection Committee.
The 10-member selection committee, comprised of athletic directors and conference commissioners, is responsible for selecting the 36 at-large teams, seeding (or ranking) all 68 teams and placing them in one of four regions within the bracket.
The selection process is based on a number of factors including win-loss record, strength of schedule and Rating Percentage Index (RPI) data.
The single-elimination tournament is nicknamed "March Madness" or "The Big Dance."
The "First Four" are the four first-round games. Two games match number 16 seeds against each other, and the other two games feature the last four at-large teams selected into the tournament. The winners advance to the second round.
Each of the four regions consists of 16 teams that are seeded number 1 to number 16. In the second round, teams are paired according to seed. The number 1 seed faces number 16, number 2 faces number 15, number 3 faces number 14, and so forth.
The sixteen teams that advance beyond their second and third-round games are referred to as the "Sweet Sixteen." The remaining eight teams are called the "Elite Eight," and the last four teams are the "Final Four."
An underdog or lower-seeded team that advances throughout the tournament is often referred to as a "Cinderella" team.
UCLA has won the most NCAA Men's Basketball Tournaments - 11.
The average cost of a 30-second commercial during the championship game in 2014 was $1.49 million.
Total TV ad spending during the tournament reached $1.13 billion in 2014.
During the tournament in 2014, there were 69.7 million live video streams across all platforms through NCAA March Madness Live, which is managed by Turner Sports.
1939 - The first tournament is held, and eight teams compete. Oregon defeats Ohio State 46-33.
1954 - The tournament final is broadcast live nationwide for the first time.
1991 - CBS begins broadcasting all games live.
1999 - CBS obtains an 11-year contract through 2013 worth $6 billion to broadcast the tournament.
2005 - College Sports Television begins a two-year agreement with CBS Sportsline.com and the NCAA for exclusive video streaming rights on CSTV.com for out-of-market game coverage. CSTV pays CBS $3 million for the rights and expects to be profitable in the first year.
March 25, 2010 - In an opinion piece on ESPN.com U.S. Secretary of Education Arne Duncan proposes that collegiate "teams that graduate fewer than 40 percent of their players should be ineligible for postseason competition and honors."
April 22, 2010 - In addition to expanding the men's tournament basketball field to 68 teams from 65, the NCAA announces a 14-year, $10.8 billion television rights deal with CBS and Turner Sports. The deal, which goes into effect in 2011, marks the first time that each game will be televised nationally.