Give me an overview of the rivalry between the Celtics and Lakers. 
 The Celtics-Lakers rivalry is an NBA(National Basketball Association) rivalry between the Boston Celtics and the Los Angeles Lakers. They are two of the most storied NBA franchises, and have met a record 12 times in the NBA finals. The first meeting in the finals between them was in 1959, and the latest was in 2010. Both teams are tied for the highest number of NBA championships at 17, and account for 34 of the 72 total NBA championships. The rivalry peaked in the 60s and 90, when the teams faced each other in the finals 6 times in the 60s and 3 times in the 90s.