NCAA Basketball 09 is a sports simulation game made by Electronics Arts. It's a continuation of the NCAA Basketball series (which used to be called NCAA March Madness). The game lets you control players in the game of basketball, either against the AI or other human controlled players on the same console or online using EA's matchmaking services. Like other sports simulation games, you control the movement and actions of individual players on the team, deciding when to pass/shoot/dribble/run plays, or do any other action associated with winning a game of basketball against a similarly motivated opponent.
The game focuses on US college basketball teams. It contains 300+ school teams and their associated rosters. The game lets you play as any of the teams, and has lots of gameplay options beyond the regular team vs. team gameplay option. It lets you simulate a season, or you can go into dynasty mode and simulate an entire career as a coach of an NCAA college basketball team. It lets you manage your roster, train players, create strategies, enter tournaments, etc. There's also an option to just play the final tournament and recreate "March Madness".
The game also has full play-by-play audio commentary by the likes of recognized sports broadcasting names like Dick Vitale, Brad Nessler, and Erin Andrews.