Liberal arts programs may ask your academic interests in your admissions application, but you are not required to declare a major until as late as your junior year. Meanwhile, at research universities, you are usually required to add your major in the admissions application. Some large schools may admit you directly to their specialized schools (such as business or music), which locks you into a program before you even enroll. You can always decide to change majors, which can be as simple as filling out a form or as complicated as re-applying to a program within the larger university if you are aiming for a selective, specialized program.