What even is it?
Investing is letting someone else use your money (capital) now with the expectation that you will receive more later.
This is through a bond, which is a loan the pays interest.
Using your money to buy real estate which can then be rented out.
Also using your money to buy shares of a business allows the business to raise money and then they pay back shareholders a portion of their earnings.
Interest in an insured savings account is low volatility low reward.
Buying company stock is a higher volatility but higher reward sort of investing.
Investing is giving up something now, for the (expected) bigger return later.
Going to college is an investment. You give up money, and time, but the jobs you can get later are much better than what you can get with a HS degree.
Exercising is an investment. You give up time now, for health later.
Watching that movie you hate with your SO, because they like, it is an investment.
Getting a CD from the bank is an investment. Instead of leaving your money in a savings account, you agree with the bank that you won't use the money for a period of time (6-months, 5-years, etc), and they agree to give you your money when the time period is over, PLUS INTEREST.
Bonds work the same way except you get interest payments over time.
Stocks, are like little slices of a company. Imagine your friend wanted a partner to open a lemonade stand. He has a great location picked out. Sign designed. A good recipe for the product, not too sweet, not too tart. But he needs $50 to get started. You agree to front him the money, and he's to pay you back half his profit. Maybe his profit is really good and he pays you back $100. Maybe it's a bad year, and he can only give you $10. But maybe that's only the first year, and he can give you $20 the second year, and $25 the third year. etc.
That first disappointing year is like 2008. A lot of people freaked out when they only got $10 bucks back the first year. and said, "screw it, I'm out." and sold their half of the profits away to somebody else. And since everyone was selling the price when down. For the lemonade stand, it would be like selling your share of the profits for 30 bucks so you at least got something. But those that stuck around (or bought in) got paid more, and more, and more each year. Eventually sales recovered. Imaging getting paid $20-$30 per year, for ever, for an initial investment of $50? Sounds pretty awesome. And as the companies do better, those returns increase, but can also decrease if they do worse. Now of course realistic returns are smaller in the 5-10% range per year. Today the Market is at an all time high.
Stocks are like your lemonade stand, except of you and a partner splitting the money, there are a Million shares out there, and people are trading them back and forth all the time. and there are a thousands of companies. It's all the same, just bigger.