In USA, a University is made up of multiple colleges, this typically consists of a "College of Liberal Arts and Sciences" (which is what most people mean when they say "college"), and one or more graduate colleges (e.g. College of Law, Medical School, Business School, etc) If an institution is referred to as a College, rather than a University, it typically means that it does not offer post-graduate programs for higher degrees (PhD, JD, Md, MBA, MA, etc)

In Canada and Germany, college is more practical. What you've learnt there is very helpful for your work in the future. However, university is more academic and has bigger scale. For example, students who wanna be lawyers, doctors, treaders, researchers should go to university instead of college.

In Australia we say university not college.

It's the same thing. You'll see "University" as part of the actual name of the institution (Example: University of XXXX); however, everyone just says college when talking.