Answer:
The US government defines college: "College: An institution of
higher learning that offers undergraduate programs, usually of a
four-year duration, that lead to the bachelor's degree in the arts or
sciences (B.A. or B.S.). The term "college" is also used in a general
sense to refer to a postsecondary institution. A college may also be a
part of the organizational structure of a university."
University is defined as: "University: An educational institution that
usually maintains one or more four-year undergraduate colleges (or
schools) with programs leading to a bachelor's degree, a graduate
school of arts and sciences awarding master's degrees and doctorates
(Ph.D.s), and graduate professional schools."
Source: http://educationusa.state.gov/graduate/glossary.htm