@jamisonic steem is beautiful and here is one of the best explaination from a new steemer what Steemit is.
"STEEMIT is bringing social networking to a whole new LEVEL. It is a decentralized (read: next level) social networking platform operating on a BLOCKCHAIN. The currency is created from people voting on the VALUABLE CONTENT of their peers.
...and its VALUE relies on its QUALITY (and the trust that we had for the author).
The best part is you do not even have to blog! You can simply upvote valuable content, comment and/or "RE-STEEM" it, and you may be rewarded for your commitment, within the next 7 days!"
by @eludelalune You can read more here of his explaination:

https://steemit.com/introduceyourself/@eludelalune/i-am-not-an-asshole#@steemisbeautiful/re-eludelalune-i-am-not-an-asshole-20170518t013700109z

Welcome to Steemit! We're happy you could join us.
Hope this Quick Starter Guide will help you:

https://www.steemithelp.net/