'Stock' in this sense means the shares that make up the capital of companies. The exchanges in London, New York, Tokyo etc are where these shares are bought and sold...ie exchanged between one owner and another.
my understanding is that all "stock markets" originated as cattle markets; so that "stock" certificates, would have indicated how much cattle you owned. as commerece spread to cover "futures investment", the name expanded into that market, as well.
Stock stands for the meaning of Share And stock exchange stands for the place where the companies or individual sell or buy this stock wheather. London stock exchange is one of the oldest stock exchange. So stock exchange plays an important role in the financial stability of the counrty of the world economy. So these are some fundamentals of the stock exchange.