I just found this while using
./craft help in the Craft CMS command line utilities:
- serve Runs the PHP built-in web server. serve/index (default) Runs PHP built-in web server.
- How to use this built-in web server?
- How can I edit these web server settings?
- Can i use multiple of these web server at once?
At this time of writing, I didn't find any documentation about that.
I'm using the latest version of Craft CMS (Craft Pro 3.3.17) under Mac OS (10.14.6).