Firefox 58 vs canvas fingerprinting: Firefox 58 will be the first major browser to do something about fingerprinting. Canvas fingerprinting is used by websites to collect data from HTML elements. With the upcoming Firefox, you will need to give your permission before data collection is allowed, just like with Tor Browser.
Fingerprinting started out as a timid practice, but has risen to prominence in recent years as an approach by companies that collect user location data without having to report it to the end user. 
It works by tracking the browser itself, rather than tracking a beacon placed in your browser, such as a cookie, a Flash LSO (local shared object), or a DOM storage value.
Beacons can be blocked or deleted, while fingerprinting cannot.
Browser fingerprints
Fingerprinting uses information passively collected by your browser, such as the version number, operating system, your screen resolution, language, list of browser plugins, and list of fonts you have installed.
There are many different ingredients that can be used to create a fingerprint, and the more ingredients included, the easier it is to identify you.
One of the most popular components uses the HTML canvas element.
Canvas fingerprinting is a surface that a browser can “paint.”
Your browser gets instructions from web pages to do something. Let’s say an image extracted from the canvas goes through a hashing operation, which produces an identifier.
Different graphics cards and operating systems work slightly differently, which means that if you give two different website visitors identical images (and the same instructions), they will produce different identifiers.
Complex instructions can produce several variants of identifiers, which makes Canvas fingerprinting a powerful data collection tool.
The more complex the instructions, the easier it is to understand the differences between browsers, and of course, to identify the end user.
To combat Canvas fingerprinting, Firefox developers have opted for the Tor Browser opt-in approach instead of an outright rejection of fingerprinting. We'll see this live in the upcoming Firefox 58.
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