Kjøpstad is a Norwegian word that means "market town". It's a place where people used to go to buy and sell things, like food, clothes, and other stuff. Kjøpstad was very important in the old days, before there were big supermarkets and online stores.
Imagine you're playing a game where you have some toys and you want to trade them with other kids. You could go to a special spot where all the kids in the neighborhood meet to trade toys. That's like a kjøpstad.
In a kjøpstad, there would be all sorts of stores where you could buy things you might need. There might be a shop where you could buy bread or meat, a store that sold clothes, and maybe even a place where you could buy all kinds of fun toys. People would come from all over to go to a kjøpstad, so it would be a busy and bustling place.
Nowadays, we don't need to go to a market town to buy things because we have stores close to where we live, and we can order things online. But in the old days, a kjøpstad was very important because it was the only place where people could get what they needed.