What is the difference between BRK A and BRK B?

Berkshire Hathaway class B is roughly worth one 1500th of class A. Originally it was 1/30. But in 2010, Berkshire B split 50 to 1. Theoretically, it would be exactly 1/1500, but class B has a lower voting right (originally 1/200, now 1/1000).