Vitrine, fenêtre, glace.

All of these are pretty much used around here Bridget. Vitrine being is the more proper term for a shop window of any size, but people will commonly say fenêtre(like the saying YUP instead of saying YES)

Regular windows are fenêtres, big or small.

Glace is used in the term "lave-glace" - the blue windshield washer fluid. Apart from that, the front window of a car is a pare-brise.

Sometimes, the word glace might be used to describe GLASS - but not necessarily in a window frame.

Confusing enough??