Why does Firefox show as my browser when I access a site, such as AOL? I thought Tor was my browser. What does Firefox have to do with this site?
Tor isn't a web browser. Tor is an anonymity network and can be used for things other than just visiting websites.
Tor Browser is a web browser. It's a fork of Firefox that's been modified and specially configured to run over Tor securely.
It's possible to use Tor with any web browser (at least in theory), but configuring your browser to use Tor effectively can be difficult and annoying, which is why Tor Browser exists.
Tor can work on both Firefox and Chrome. Its like an add-on and not a browser in and about itself.
You can also install a button on your chrome to toggle Tor on and off which is much quicker than launching Tor again and again separately.
Here is a good guide on how to do it plus some more tips and explanations that will help you better understand how Tor works.