System updates to 2014 MacBook Air

An Early 2014 MacBook Air can upgrade as far as macOS 11 (Big Sur) – but no further.

If you upgrade to Catalina or Big Sur, 32-bit applications will stop working. Also, iTunes will go away, replaced by separate applications (Music, TV, Podcasts, Books, and Finder-based iPhone/iPad/iPod management).

You can get Big Sur using the link in this article. If you normally use some browser other than Safari, temporarily make Safari your default browser, and use it to access the Support article. If you access the App Store links with other browsers, you may get misleading error messages that say that the item you want isn't available.

How to download and install macOS - Apple Support

Since Apple ties Safari updates to macOS updates, and Big Sur is no longer one of the "most recent three" versions of macOS, you may want to install another Web browser, like Firefox.

The current version of Firefox will run on Catalina and Big Sur.

https://www.mozilla.org/en-US/firefox/new/