Business school is a place you can go to study better about business management and probably entrepreneurship. It is a school laid than for the purpose of building people in the business field. However, coming to look at it critically, you will notice that even the most successful and richest entrepreneurs in the world did not go through business school.
Taking a look at Bill Gates, he started at Harvard with law, after which he moved to another department but ended up dropping out. He didn't pass through any business school, but he is a business tycoon. Another successful entrepreneur is the old Warren Buffet, the CEO of Berkshire Hathaway.
This man actually studied business administration, and he had his degree of Bachelor of Science in the field. This is a man that went through the business school and still a successful entrepreneur. However, most of the successful entrepreneur did not go through the business school, but they keep educating themselves in the business line.