Halea, this is a great question and something that can seem very confusing when you are applying to colleges or in college. Ideally, your academic advisor and/or career counselor at your university will have discussions about this with you so you should reach out to them. Competing internships while in school is a great way to develop contacts at different organizations and learn more about your chosen field. You may also want to look into conducting some informational interviews with people who have jobs that you find interesting. There are several websites which can tell you more about informational interviews such as how to ask for one and conduct one in a professional and respectful way. Without knowing more about your career choice, it would be difficult to guide you further but you can't go wrong with internships. Even if you only learn from an internship what you don't want to do, at least you are wiser than before!