a modern stock market is different than it was ten-twenty years ago, when a strategy buy-and-hold was good enough. Now it is much harder to have a decent investment return without a proper research and analysis.
A stock market or equity market is a public (a loose network of economic transactions, not a physical facility or discrete) entity for the trading of company stock (shares) and derivatives at an agreed price; these are securities listed on a stock exchange as well as those only traded privately.