Today there was a lot of scarey stuff released about WiFi!  KRACK is a new and fun way to replace the Wifi key your computer or phone has setup with the router, which allows someone to force your devices to act unsafe.  Lets relax a bit, but be aware.
The immediate danger is that someone is tracking your login with a redirect to a non-ssl site.  So, make SURE that if you are entering a password, the page you enter it on has a little lock up there.  A nice pretty green lock and says all is still locked up and using secure protocols.  More patching will follow over the next few weeks, Microsoft and Apple both say patches are forthcoming, Android phones since version 6. will be updated soon.  Just be safe!
If you have questions, we really don't have any other answers yet.  Patches are forthcoming from all the vendors (it appears) so in a few weeks this will be old news again.
Remember, it requires someone else be on YOUR network to see the packets.  So if you are at home, you are probably fairly safe, but in a public hotspot you are very much NOT safe.
In depth details: