Mozilla has expanded its Total Cookie Protection feature, which prevents cookies from tracking you across websites, to its Firefox Focus browser on Android.

Cookies are the primary reason we search for a product on one website and then suddenly see ads for that product on another site, and they pose a privacy concern for many. Mozilla addressed this last year by introducing Total Cookie Protection to the Firefox web browser, but it was limited to PCs. Now Android users can take advantage of the same protection that's been added to the Firefox Focus mobile browser, which Mozilla is touting as a mobile "companion app."

The way Total Cookie Protection works is relatively simple (functionally, at least). The way Mozilla describes it is that most browsers have one big cookie jar that all websites can pull cookies (tracking data) from. Total Cookie Protection organizes all of those cookies so that each website has its own "jar", which is the only source that each site can pull from. So, essentially, any website you visit can only track your activity while you're on that specific website – once you leave, that site can't see what you're doing elsewhere.

Under the hood, it’s a bit more complicated, as many sites are built to track you and wouldn’t function properly otherwise. But according to Mozilla, there are additional measures and solutions to keep everything working while still protecting your privacy.