If you experience something, you go through an unusual or exciting event. If you're experiencing the world's loopiest roller coaster, you'd better hope that the amusement park doesn't experience a power outage.
Sometimes experience means accumulated knowledge and sometimes it refers to a single spectacular event. If you have experience in cooking, you have worked in a restaurant before. Learning by experience is a method of acquiring knowledge by doing and not by reading. On the other hand, when you come back from summer camp, your mom will want to hear about your experiences. And white-water rafting is quite an unforgettable experience.