So far there’s three patches to write about, all of which are not enabled by default. The first patch is aimed at reducing or removing browser fingerprinting. This is, if you aren’t aware, information that can be extracted from your web browser by the websites you visit. Some consider it a violation of privacy as this information can potentially lead to personal identification. It has non-malicious purposes too, such as analytics and preventing Internet identity fraud. Firefox accomplishes this by restricting the ability to read plugins and MIME types that the browser supports.
The second patch is also directly related to device fingerprinting – when a page requests screen.orientation.angle and landscape-primary, Firefox will return a value of 0, rendering the site or application’s request useless.
And the last one is fairly simple – it allows for removal of the “open with” option after downloading a file.https://www.deepdotweb.com/2016/07/10/mozilla-implementing-tor-privacy-features-firefox-builds/