Quote:The built-in screenshot tool of the Firefox web browser was added to the web browser in 2017 after it was released as a Firefox's Test Pilot before. The screenshot tool was not the first native option to take screenshots in the browser as Firefox's users could take screenshots from the (now retired) Developer Toolbar from 2012 on.
Mozilla moved some of the functionality to the Developer Tools of the browser, but the main way of taking screenshots in Firefox is by using the built-in Screenshot tool.
Mozilla improved the Screenshot Tool in recent versions of the browser; it includes a basic editor now to make some adjustments to the shot.

Full reading: https://www.ghacks.net/2018/10/04/mozilla-plans-to-change-confusing-screenshot-tool-terminology/