In that case, it is possible to invest passively in capital markets. This means that a private investor puts aside either a lump sum or an amount each month and the money is invested into a fund. That fund contains the savings of lots of other private investors and is managed by a professional equities investor. The fund will then be invested in an equity market (such as the NYSE) or a sector (such as energy).
Bonus Stock Market Tip: Everything above is related to how best to invest actively - in other words buying and selling into companies that have been selected by you. But what if you don't have the time, money or inclination? What if the paragraphs above put you off? Perhaps you were looking for a simpler guide? The stock market for dummies perhaps?
A broker is simply a licensed person through whom you can buy and sell these stocks. When you use an online platform, it essentially acts as an online broker. If someone wants to buy any product, he can contact a brokerage service. They would place an order and let him know the market price of the product. If the investor is interested, they would include a commission for themselves and process the order forward. If the user wishes to buy stock, the broker would forward his order to a stock exchange, which would approximately take 3 days to complete including the money exchange between the broker and the investor.