The UNIX operating system is a powerful, multiuser, multitasking OS widely used in servers, workstations, and mobile devices. Developed in the late 1960s at AT&T’s Bell Labs by Ken Thompson, Dennis Ritchie, and others, UNIX became foundational for modern computing. It is known for its modular design, portability, and efficiency. The system’s core, or kernel, manages hardware, file systems, and system calls, while a shell provides a command-line interface. UNIX inspired many derivatives, including Linux and macOS. Its reliability and robustness make it ideal for complex environments like programming, networking, and enterprise systems. It’s a cornerstone of IT infrastructure globally.