One of Firefox’s strongest privacy features, Total Cookie Protection was first introduced with the Firefox 86 release of the open-source web browser, was extended to the Private Browsing mode with the Firefox 89 release, and further improved in Firefox 91 to prevent data leaks.
If you haven’t heard, Total Cookie Protection protects your privacy by confining cookies to the website where they’re created. This prevents tracking companies from using the said cookies to track your browsing activity as you navigate across multiple websites.