Earlier quoted context omitted.
- Yes, Firefox does support Containers, which are a very innovative privacy feature allowing you to maintain separate browser sessions (cookies, site preferences, ...) towards different websites inside a single browser instance.[1][2] [1] https://support.mozilla.org/en-US/kb/containers#w_what-are-c... [2] https://www.thechiefmeat.com/guides/containers.html
Not by default though. You need to install the "Multi-Account Containers" addon if you want to activate it.
[1]: https://addons.mozilla.org/en-US/firefox/addon/temporary-con...
[2]: https://github.com/stoically/temporary-containers
[3]: https://addons.mozilla.org/en-US/firefox/addon/facebook-cont...
[4]: https://addons.mozilla.org/en-US/firefox/addon/google-contai...