What are “Futures” charts actually showing me?

I basically understand what Futures are, but when I go to MarketWatch and see the Futures charts at the top, I'm not sure what it's telling me.

Example: Nasdaq is currently at 11,805 – Click Futures and “Nasdaq F” is 12,364.

Side question, is a futures chart even relevant to the direction of the normal chart? Like if futures are up should I expect things to be moving up the next session?