system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The Stock Market and how I can get involved.
gpt
A market is a place (or virtual place nowadays) where people meet to trade things.

A stock market is a place to trade stock (shares of a company). There are commodity markets, bond markets, candy markets (in pre-school classrooms). Pretty much anywhere people have things that they do not need and would value having something else more you'll find a marketplace ready to trade in it.

You can best get involved by doing some research on what kind of company's stock you'd like to own. Once you know this you can contact a broker (or maybe your bank) to open a trade account and purchase the shares. 

I strongly suggest that you buy things that are undervalued and sell them when they become overvalued (i.e. buy low, sell high). That strategy seems to work for Warren Buffet.