Sellers are able to enter and exit the market freely.A flea market is very much an example of ready access to enter and exit a marketplace. There is no monopoly of one company or group on the trade there; individuals are able to set up their booths and market their products at will. Marielle's knitted items will have her own unique touch, so the "identical products" aspect of pure competition doesn't so much apply here. And while you'll find many sellers at a flea market, they're all selling their own various, different items.
Overall, the basic characteristics of what is called "pure competition" are these:
... There are many competitors selling similar or identical products.
... When products are similar or identical and are all selling at similar or identical prices, no one competitor in the market has a distinct advantage over others.
... New competitors can easily enter the market, and competitors can exit the market. (That's the key feature in your flea market example.)
... Product prices are essentially whatever buyers are willing to pay.
