MacOS is a Unix operating system. It is certified as a UNIX 03-compliant operating system by The Open Group, which is the organization that owns the Unix trademark. This means that macOS meets the requirements of the Single UNIX Specification (SUS), which is a set of standards that define what it means to be a Unix operating system.
Being a Unix operating system means that macOS has a number of features that are common to other Unix-based operating systems, such as:
- A layered architecture, with a kernel that provides basic services and a userland that provides the user interface and other applications.
- A file system that is organized in a hierarchical structure.
- A command-line interface (CLI) that allows users to interact with the operating system from the command line.
- A set of standard utilities, such as ls, cat, and grep, that can be used to manage files and directories.
Being a Unix operating system also means that macOS is compatible with a wide range of software that is written for other Unix-based operating systems. This makes it a good choice for developers and users who need to run software that is not available for other operating systems.
Here are some other operating systems that are also considered to be Unix:
- FreeBSD
- Linux
- Solaris
- HP-UX
- AIX
I hope this helps! Let me know if you have any other questions.