This article lists the different MacOS generations and version history

The Macintosh operating system has gone through several generations of development and evolution, including the following:

1. System 1-6: The first six generations of the Macintosh operating system, released from 1984 to 1990. These early operating systems were limited in functionality and were replaced by the more advanced System 7.
2. System 7: Released in 1991, System 7 was a major upgrade from the previous Macintosh operating systems. It introduced new features such as virtual memory, personal file sharing, and improved color support.
3. Mac OS 8-9: The next two generations of the Macintosh operating system, released from 1997 to 1999. Mac OS 8 introduced features such as the Appearance Manager, which allowed for customizable interface themes, and Mac OS 9 added support for multiple users and improved system stability.
4. Mac OS X: Released in 2001, Mac OS X marked a significant shift in the Macintosh operating system, introducing a completely new architecture based on Unix and a more modern and sophisticated user interface. Mac OS X has undergone several updates and versions, including:

• Mac OS X 10.0 "Cheetah"
• Mac OS X 10.1 "Puma"
• Mac OS X 10.2 "Jaguar"
• Mac OS X 10.3 "Panther"
• Mac OS X 10.4 "Tiger"
• Mac OS X 10.5 "Leopard"
• Mac OS X 10.6 "Snow Leopard"
• Mac OS X 10.7 "Lion"
• OS X 10.8 "Mountain Lion"
• OS X 10.9 "Mavericks"
• OS X 10.10 "Yosemite"
• OS X 10.11 "El Capitan"
• macOS 10.12 "Sierra"
• macOS 10.13 "High Sierra"
• macOS 10.14 "Mojave"
• macOS 10.15 "Catalina"
• macOS 11 "Big Sur"

iOS: Separate from the Macintosh operating system, iOS is the operating system used by Apple's mobile devices, including the iPhone, iPad, and iPod Touch. It has also undergone several generations of development and evolution, with the latest version being iOS 14.