In American English all universities are colleges, but all colleges are not universities. Institutions that call themselves colleges (for example community colleges) are often not big enough to qualify as universities. Other names for colleges are "academy" and "institute", as in Massachusetts Institute of Technology.
In British English a college is a residence hall and an independent part of a university. Colleges admit their own students, provide accommodation, meals, common rooms, libraries, sports and social facilities. Through the tutorial system they also teach students. In later years the American meaning of the word has come to be used along with the British meaning.
The German word for college is Hochschule, literally meaning high-school, which can be confusing enough.
See colleges and universities for a list of some famous colleges and universities.