Mozilla introduces updates to tab management in Firefox
Link: https://support.mozilla.org/en-US/kb/tabs-organize-websites-single-window
Discussion: https://news.ycombinator.com/item?id=41463660
Use tabs to organize lots of websites in a single window | Firefox Help
By displaying a website in a tab, Firefox lets you have multiple websites open inside a single window. Learn the basics of using tabs.support.mozilla.org