macOS Big Sur is a major release of macOS, Apple's desktop operating system for Macintosh computers. It is the successor to macOS Catalina and is the first with its major version number changed, now known as macOS 11.0. This utility software offers a major user interface redesign, several improvements to other features, and Apple-designed ARM processor support. However, unlike Catalina, it drops support for various Macs released in 2012 and 2013.