A stock is a share of ownership in a company. When you buy a company's stock, you are buying a small piece of that company. If the company does well, the value of your piece might go up. If it does poorly, the value might go down.

Companies sell stocks to raise money. They use this money to fund their operations, expand their business, or develop new products. In return for their investment, shareholders get a claim on the company's assets and earnings. Sometimes, they even get a say in how the company is run through voting rights.

Stocks are bought and sold in a marketplace called a stock exchange. These exchanges are organized platforms where buyers and sellers come together to trade shares in a regulated, fair, and transparent way. They act as intermediaries, matching the person who wants to sell a stock with someone who wants to buy it.

Without exchanges, finding someone to buy your specific shares at a fair price would be incredibly difficult. The exchange provides liquidity, which means you can buy or sell stocks quickly without causing a major change in the stock's price.

Two of the most famous stock exchanges in the world are located in the United States:

• The New York Stock Exchange (NYSE): One of the oldest and largest exchanges, it's known for its physical trading floor where brokers have historically gathered to execute trades. Many of the world's most established companies are listed here.
• The Nasdaq Stock Market: This is a newer, all-electronic exchange. It's home to many of the world's leading technology and growth companies, like Apple, Amazon, and Microsoft.

Exchanges exist all over the world, such as the London Stock Exchange (LSE) and the Tokyo Stock Exchange (TSE).

How does a stock actually get from a seller to a buyer? It happens through a series of bids and asks. The price of a stock is determined by supply and demand.

• Bid Price: This is the highest price a buyer is willing to pay for a stock.
• Ask Price: This is the lowest price a seller is willing to accept for that same stock.

A trade occurs when the bid and ask prices meet. This constant negotiation between buyers and sellers is what makes stock prices fluctuate throughout the day. The difference between the highest bid and the lowest ask is called the "spread."

To participate in the stock market, you'll typically need to open an account with a brokerage firm. The broker acts as your agent, executing buy and sell orders on your behalf on the stock exchange.

Ready to check your understanding? This quick quiz will cover the core concepts we've discussed.

Understanding these basic building blocks is the first step. You now know what a stock represents, the crucial role of exchanges, and the fundamental process of how shares are traded.