Analogies with stores/checkers/soda etc. are all flawed because they are based on something that does not exist in the markets, that is a fixed price. When you buy a physical good in a store they have a published price that you can trust to be what you will pay (in western countries that is the norm, not so in many other places.)<p>Conversely, when talking about equities markets there is no such thing as the stock "price". This is a short hand that is used. In reality, there are groups of people, some willing to buy shares at a variety of prices, and some willing to sell shares at a variety of prices. The job of the exchange is to match these 2 groups when the buy/sell prices intersect or cross. This gets complicated when there is more quantity on 1 side of the buy/sell than the other. Exchanges have rules how this imbalance will get resolved, most of the time it is based on who has been at that price point the longest.