Can someone explain STEEM power to me>

This post sums it up really good:
https://steemit.com/steem-help/@sykochica/answering-common-questions-steem-steem-power-steem-dollars-and-what-should-i-do-with-them

https://steemit.com/steemit/@thecryptofiend/the-missing-faq-a-beginners-guide-to-using-steemit

I thought this broke it down pretty well.

Start from here, read all of it and then start asking questions.
https://steemit.com/welcome