Big Sur is officially macOS 11.0

The original version of Mac OS X (which Apple renamed macOS to better match its iOS, watchOS, and tvOS software brands with the release of macOS Sierra in 2016) was released as a public beta for $ 29.99 in September 2000, as the successor to Mac OS 9, the last of Apple's "classic" operating systems dating back to the original Macintosh in 1984. The launch of Mac OS X was a dividing line in the sand between the original era of Apple computers and the birth of a new generation of devices.
Apple would spend the next decade refining and improving OS X, with updates released much more sporadically than the now-yearly releases that have come to define all of the company's software. Older versions of OS X, famously named after their "big cat" codenames like Jaguar, Lion, Leopard, and Tiger, were actually paid upgrades that customers had to buy, not free downloads. OS X also spanned generations of Apple hardware, from the early PowerPC days of the iMac and MacBook, through the Intel switch of 2005, to newer devices like the Ultra-thin MacBook Air or the astronomically priced Mac Pro.
Beginning in 2011, Apple would begin to switch to annual OS X releases; In 2013, with the release of OS X Mavericks, the company would ditch the cat names and turn OS X into free annual updates.

The move to macOS 11.0 is surprising for Apple, given that at one point it seemed like Apple was married to the idea of ​​simply using OS X / macOS 10 as its brand name for its software for the foreseeable future. Microsoft had even started to stick with the suite, with the company stating in 2015 that it viewed Windows 10 as the "final version of Windows."

However, with Apple moving to macOS 11, it's up to someone to guess what happens next. Will next year see a shift towards iOS-like version numbers with the release of macOS 12? Or have we started a new era of macOS 11 updates, with version 11.1, 11.2, set to be released every fall for the next two decades?

However, the change now marks a fitting end for OS X, however, as Apple begins its latest reinvention from Intel-based chips to new ARM-based Apple Silicon products that will further blur the lines between its iOS and iPadOS mobile devices. and your laptops and desktops.

OS X defined the Mac for generations of hardware and software. It will be exciting to see what Apple has planned next.