What is graduate school like? How is it different from other schooling?

Graduate school is like no other beast. In the sciences, you both do research and take classes. When you start out, you are mostly taking classes but, as you progress, you do more and more research with fewer to no classes. By the time you graduate, there is little difference between being a graduate student and being a postdoc or research scientist. It is a transition and learning period. By the end, you are the world expert on the topic of your research. Answers are not in the back of a textbook or online. You make your own questions.