As part of Googles security you are provided with alerts when your password is changed, if you do not reckonize the location and IP address you can report it. I received about 4 notifications of my password being changed with IP addresses and locations. However two of the alerts have IP addresses in a form I have never seen. My question is what kind of IP address are these
Those are for a new(er) form of addressing called IPv6.
In short, they made IP addresses in version 6 of the Internet Protocol service into something with much larger numbers that give us literally tens of billions more addresses than IPv4 (what we use today) gave us.
This Wikipedia article has a pretty good rundown.