Polish gimnazjums - memoirs of a teacher

This chart might explain it better...

Many people take the associate degree in their home town to knock off the basic subjects. It's cheaper as many live with their parents and usually there's a lower "in-state" tuition. Then they proceed to the college of their choice to specialize in their field of interest and get a bachelor in science, bachelor in arts, - applied sciences, - computer technology, - aerospace, etc. Some go to the college of their choice from the get-go and skip the associate degree. (it'll still take about the same time but you won't have to change schools).

Some continue on to earn a masters degree , ph.d, etc.
upload.wikimedia.org/wikipedia/commons/8/81/Education_in_the_United_States.svg

It might differ across the English speaking countries but "college" to me isn't really something specific. It may very much depend on what goes in front of the term though. Certainly if you said you were at "technical college" the assumption would be that it was some sort of specialised institution with a mechanical/practical aspect and not what would be understood as a university.

For me, the phrase "when I was at college" though tends just to mean "at 3rd level education" and is the phrase used instead of, for example, "during my studies" which is what Poles seem to say.

"University", as a term, is much less prestiguous than it once was for English speakers - many colleges in the UK that were previously known as "Polytechnics" for example became universities in the last couple of decades - and not necessarily through any vast improvement in reputation/ethos or whatever.