Final answer:
The Boston Celtics have won 17 championships, establishing them as one of the most successful teams in NBA history.
Step-by-step explanation:
The Boston Celtics have won a total of 17 championships. This number places them among the most successful teams in the history of the NBA. Their victories span across several decades, with their most recent championship occurring in 2008. The Celtics have a storied rivalry with the Los Angeles Lakers, who also have a significant number of championships.