The stock market brings together people who want to sell stocks — also known as shares — with those who want to buy them. When you invest in a company’s shares, the hope is that the value of those shares will go up over time, resulting in a profit for you. You can invest in individual stocks, or purchase a basket of stocks through mutual funds or exchange traded funds (ETFs).

A stock’s price is determined by supply and demand on the market, which you can access through brokerage accounts. For example, when a new company lists its shares publicly through an initial public offering (IPO), those shares will enter the secondary market where they are bought and sold by investors. If lots of investors are interested in a stock, that will push up the share price, which may entice current shareholders to sell for a profit.

Regulators are in place to help ensure fair practices, protect investors and promote confidence. These agencies include the Securities and Exchange Commission, which regulates trading in shares, as well as the Financial Industry Regulatory Authority, which is more focused on protecting retail investors (and is the entity that oversees brokerage firms and registered securities representatives). And because the stock market is global, calamities in one part of the world are quickly felt around the world. This is why it’s important to diversify your investments and stick with a long-term investing plan.