At crossings of traderoads (over land and water) often, places were set up for (year)markets. These places were often occupied only a part of the year, but the most important ones grew out to permanent settlements and eventually complete towns. Think for example about Noviomagus, „new market“, the present Nijmegen – still very strategically situated. Many houses were occupied by craftspeople who often besides that were tradespeople as well. Their houses had a combined function of living and a shop, even with an own workshop added to it. The carpenter, typically, who made furniture in his workshop, would surely have some space which he used as a present day „showroom“.
Probably, the arranged trade (planned shops in buildings that is) evolved from selling at markets, hawking and peddling. The division between craft and trade used to be less clear or non existent. Trade used to be more direct, i.e. with less chains in between – quite different from today, that is.
Furniture and clothing will probably be made on order, when one could afford it.
Besides this craft and trade function avery important market function in the late medieval cities was played by the nearby living farmers. A city was dependend on the surrounding countryside. Therefore, everybody from the far surroundings was obliged to sell his or her products at the nearby town first. Such tradespeople in fresh food will mostly have traded out of market stands.