In American English, college and university are generally used interchangeably, but there are some subtle differences between them. University usually denotes a school that offers full undergraduate and graduate programs, while colleges usually offer more narrow programs and may have no graduate studies at all. But there are no official designations for these terms, and colleges and universities can call themselves what they want.
In practical American usage, university has connotations of prestige that college doesn’t have, although there are some highly respected universities that call themselves colleges out of tradition (e.g., Dartmouth College). Still, no one talks about going to university in the U.S. After high school, you go to college, even if the college you’re attending calls itself a university.
In the U.K., universities are institutions that award degrees, while colleges are institutions that prepare students to earn degrees. The system can be rather complicated and varies from school to school. In practical usage, British English speakers generally use university as the generic term for higher education.
Hope that clears it up. LOL