If I want to buy something, I go to a store or hit up the internet. In the science fictional future, I might 3D print many of the things I need, without having to go anywhere or wait for shipping. In a heavily fantastical world, maybe a spell might fill the same niche, teleporting my goods to me or conjuring them out of thin air.
But for many people at many points in history, you couldn’t just acquire whatever you wanted, whenever you wanted. You had to wait for a market to happen.
A market can be any venue where things are bought and sold, e.g. a “marketplace” in the sense of a fixed and permanent institution, or even a “market” in the more abstract sense that economists use the word. Here, though, we’re talking mostly about periodic markets: ones that aren’t there all the time.
Anybody who’s attended a farmers’ market knows the general drill. Once a week, usually, but sometimes on a different schedule like once every two weeks, area farmers congregate in a useful location to hawk their wares. My local market includes a lot more than just fresh fruit and vegetables: you can also get meat, eggs, cheese, honey, flowers, seedlings to grow at home, and a wide variety of cooked foods. Even other products like soap! Organized households may do most or all of their week’s shopping at the market, at least in the categories that are on sale there, while others go to buy a few things and enjoy a stroll around the place, stopping to chat with the friends they see.
That “once a week” setup isn’t just a natural approach to scheduling; it’s actually the source of our scheduling. In many parts of the world, the length of a week was originally based on the frequency of a given market. You might have multiple such events in a week, but each one would be in a different location (as is the case with farmers’ markets in my area), alternating in a regular series.
Markets are a sensible way of handling certain types of trade in the rural life of a pre-industrial society. Most of people’s day-to-day requirements are supplied at home or within their immediate community; commerce of the sort we take for granted simply isn’t a feature of how they live. But even within a small region, one area may be better for growing a particular type of crop than another, and there are specialized crafts like pottery or blacksmithing that not every village will have locally. To get things not available in your village, or to dispose of the materials your village produces, you have to go elsewhere — and since travel is slow and difficult, you don’t want to be doing that on a daily basis. Hence markets: organized events where you know other people will be present, ready to trade with you.
The scale and focus of a periodic market ranges all over the place. The weekly market will often be the most local one, with little in the way of specialized goods on offer; there will be many of these, all quite small, but the lifeblood of the communities they serve. The settlements that host these events tend to be the larger ones, or else they grow larger because of the market, becoming proper towns. (In Britain, a “market town” was a legal category, with a charter permitting the residents to host such things.) When we speak of the market square in an older town — or attach that name to a downtown area in a newly-built modern community — we’re nodding toward the tradition; this was the open area where people would set up their wagons and stalls to sell their goods.
Bigger markets may happen less frequently, perhaps once a month, in larger towns that people travel longer to get to. Here you can get more exotic or elite wares, in part because larger towns have more wealthy inhabitants who can afford such things. And then certain trades may have seasonal or yearly markets that focus specifically on their product, though any number of ancillary activities can attach themselves to the big event.
If that last point is making you think of the word “fair,” you’re not wrong. Any market is at least a minor festive event, because it’s an excuse to get away from the humdrum routine of your daily life and go someplace different. At a big enough market, you may have entertainers like musicians or acrobats, or prepared food for sale that isn’t what you eat at home. The bigger the market, the more of a festival it becomes. And if you live in, say, a sheep-herding area, then the annual wool fair will draw people from far away — even from foreign countries! — to buy the results of the year’s shearing. It doesn’t get more exciting than that!
As commerce grows and settlements build up in size, what started as a periodic market may transition to a permanent one. You can think of it like gravity, or like a self-sustaining reaction: because trade gravitates toward larger, more centrally-placed locations, city-dwellers aren’t generally going to travel to some smaller town to buy what they need. And because there are so many people in a city with constant needs (and the money to spend on them), trade becomes a constant thing rather than an occasional one.
So while you still have markets in a city, they’re a bit of a different beast. Here you’re likely to get markets that resemble the specialized annual fairs, but ongoing: a bean market, a rice market, a flower market, a fruit market. Every morning you might go to the fish market for the day’s catch, or to the meat market where freshly-slaughtered livestock are available. All of this is supported by a (hopefully) uninterrupted stream from the countryside, continually feeding the city’s voracious maw.
And, of course, you have all the specialized goods I mentioned before. But those still may not be sold in shops like we’re used to, nor in the fixed marketplaces of basic necessities. Sometimes, instead of you going to the store, the store comes to you . . .