The Macintosh OS is derived from an original version of Unix. As such, it’s considered Unix – not just Unix-like.
reference: https://www.howtogeek.com/441599/is-macos-unix-and-what-does-that-mean/
This has implications from how software is installed to the directories where programs and data are stored.
One place to view a Macintosh displaying that it is in fact Unix is the apache2 command: apachectl -v
Last login: Thu Feb 20 13:00:30 on ttys000
computername:~ username$ apachectl -v↵
Server version: Apache/2.4.33 (Unix)
Server built: Apr 3 2018 17:54:07
computername:~ username$