register 和 sign up 和 enrol 有什么区别？如果难以说明的话，请教我一下例句。

Each of the words are similar but may be used in different ways. To register and sign up is to dedicate oneself to something or join something. Ex: I signed up for the new gym across the street. Ex 2: I registered for that new website. To enroll means to also join something, but when I hear this word I think of university or school.ex) I enrolled in a summer course at school. I enrolled on campus last winter.