Stained glass was used in the Middle Ages predominantly in churches and cathedrals as a way for the illiterate to learn biblical stories; the glass would usually have depictions of the Bible on them. Catholic churches have much décor in the form of statues, overall design, and stained glass, as opposed to the more simplistic Protestant churches.

In addition, with the onset of Gothic architecture, windows became larger and larger in cathedrals, as you can see for example in the interior and exterior of Reims Cathedral in Reims, France. This provided room for more glass designs.

There wasn't much use for colored glass in a peasant's home, if they even had windows. Glass windows were rare for peasants to have due to their high cost and value. Mostly, the only buildings with glass windows were those owned by the nobility or ecclesiastical figures. However, peasants sometimes would have openings in their houses with shutters they could close.

This is very anecdotal I know this tends to be not allowed on the sub, but in the house we lived in, located in a small German town there were several rather large stained-glass windows. IT was a common feature throughout the town, many of the homes and businesses had a lot of stained glass.

I do not have pictures on this computer.

Sheet glass didn't exist in the Middle Ages, people didn't know how to manufacture it. The only way how to create glas windows was exactly stained glass, and since it was expensive, they had all reasons to create a mosaic out of it. An average person could by no means afford such windows.