The command line and other Unix-like aspects of Apple's macOS
Apple's macOS (formerly known as OS X and Mac OS) is a Unix variant built on a Mach/BSD-based kernel and FreeBSD-based userland. On this site, we cover the DevOps-like aspects of the system, including the command-line interface, the filesystem, etc. Question about things that aren't Unix-like (including most of the graphical user interface) are covered at our sister site Ask Different.