Unix is a family of operating systems, traditionally running on server and datacenter grade equipment.
Developed in 1970 by AT&T (most notably by Ken Thompson and Dennis Ritchie), Unix started as an in-house development project to create a multi-tasking operating environment supporting multiple users connecting and interacting with a single computer system.
Most of the current Unix, Unix-like and Linux systems borrow majority of concepts from the original Unix implementation.
In fact, large number of the commands found in every modern Linux distro go back to the initial implementations of same Unix commands back in original Unix distributions.
Each system aspiring to be called and marketed as Unix OS must pass a certification process to ensure it meets design and implementation standards.
Unix Operating Systems
- macOS developed and distributed by Apple