The reason we have a stock market is that companies need capital to be able to expand their business, and those with capital, who want to increase said capital, need something to invest in. It's a lot like a bank loan.

As for the why people buy stock, or lend a company their money - it depends. Sometimes, it's an investment in the future of the company. You're hoping they're successful, and if they are, then your share (your piece of the pie which is essentially a percentage) will increase in value (the pie gets bigger, and the percentage you own stays the same, and thus you end up with a bigger slice) That's what investing is. Swing trading, which is what OP is doing is taking advantage of swings in the perceived value of a stock. Current events, along with people's worries, and expectations will cause the average perceived value of a stock to change. Sometimes they're correct in their worries, and expectations, sometimes not. With swing trading, you're making a bet on the short term outcome. Then when things come to pass, you sell what you bought, or buy back what you sold, and make money. With swing trading, you're making short term predictions based on the happenings of today - where a company will be relative to where it is now, tomorrow, or a few days from now. With investing, you're making predictions regarding where a company will be a year from now, or even longer. Then there's day trading, which is absolutely insane.

do you get a say in how the company operates or something?

Not with the amounts of stock that people like you, OP, and I have the potential to play with.

is there an actual real value behind it?

Actual, yes. When you own stock, you own a piece of that company. Real, no. When you trade stock though, you're buying or selling it according to its percieved value. There is nk such a thing as "real" value, as value is something which is subjective.