(adsbygoogle = window.adsbygoogle || []).push({}); When in an internet browser, (not sure if all, but IE for sure) when you press F12, it opens the developer tools. What exactly is this and what kinda fun could I possibly have with it?

Mostly to debug a site. I use to tweak css live to see what needs a fix.

You cant edit the Script and all that you can just see it, I've tried it, all you can do is run scripts that are already set on there, cant create any, well at least i tried and it wouldn't let me

Ive messed with it before and was able to change the layout of a webpage, just like buttons and certain text but they were all messed up and weird looking.