This is an amazing extension, and happens to be one of the reasons Firefox is my primary browser. It gives you the ability to (1) separate tabs into "work" and "personal" containers (or any other organization you would like) allowing you to be logged into different accounts simultaneously on the same platform. And (2) it gives you the ability to keep trackers localized to a single website, so it's completely impossible for them to follow you around to other sites.

It can be a little confusing to set up (make sure to tell it to "Always Open This Site In..." when you've opened a site in a new container, so it does so automatically), but I honestly couldn't imagine using the internet without it anymore.