Could someone explain how payment works on Steemit?

Hello everyone!

I am very new to Steemit and one thing I still don't understand is the payment system. I have looked for information all over the place, and despite reading tons of articles and watching videos, I'm still as confused as can be.

So, could someone explain to all this works in plain English?

What are Steem Dollars and Steem Power?

How different are they from each other?

Once payment has been released, how do you get your money?

Can someone get their money via Paypal? If not, what can you use?

Thank you for your help!