Which operating system is Linux based on?

Linux is indeed based on UNIX. The development of Linux began in the early 1990s by Linus Torvalds, who was inspired by the design principles of UNIX. UNIX is a powerful, multi-user, multitasking operating system that has significantly influenced many other operating systems, including Linux.

The core of Linux incorporates many features from UNIX, including its file system structure and command-line interfaces. Moreover, Linux adheres to the POSIX standards, which are specifications that describe the application programming interface, along with command line shells and utility interfaces, to make an operating system compatible with UNIX. This close relationship allows users of UNIX systems to easily transition to using Linux, and vice versa, further establishing Linux’s UNIX-like nature.

In contrast, other operating systems mentioned do not share this UNIX lineage. Windows is fundamentally different in architecture and design, macOS, while built on a UNIX-like foundation called Darwin, is not directly derived from UNIX in the same way Linux is. Android is based on the Linux kernel but is tailored for mobile devices, diverging from the core UNIX principles.