NBA (National Basketball Association) – The professional basketball league formed in 1949 which now consists of 30 teams (29 U.S., one in Canada)  

NCAA (National Collegiate Athletic Association) – An association of more than 1,200 colleges’ and universities’ athletic programs
 
NCAA Tournament -- A yearly competition to determine the national college championship team from 64 eligible college teams. Referred to as “March Madness” because it occurs in March. See “Final Four”
 
NIT (National Invitational Tournament) – A collegiate basketball tournament that predates the “NCAA Tournament” by one year, currently owned by the NCAA and sometimes referred to as the “Not Invited Tournament” because it consists of teams not invited to the “NCAA Tournament”