Both belong to tertiary education. Colleges are smaller institutions of higher education which offers undergraduate degree. Some of them, like community colleges or junior colleges lasts for two year but the length of education time can differ, for example, some of them lasts for four years, still, it is a college. Universities, on the other hand, offer not only undergraduate degree but graduate ones as well, like master or PhD. They have more diverse educational program in order for the students to obtain a more rounded knowledge. Medical or law schools are always universities.
