If you try to start up your Mac from a hard disk, network volume, or Time Machine backup that contains an incompatible version or build of macOS, you might experience one or more of these symptoms:
Apple Mac OS 9 CD Computer Software, Waves Mac Pro Audio Software, Loops & Samples, Apple Mac OS X 10.11, El Capitan Operating System Software, Apple Mac OS X 10.0, Cheetah Mac Computer Software, Apple Mac OS X 10.4, Tiger Mac Computer Software, Apple Mac OS X 10.3, Panther Mac Computer Software, Apple Mac OS 9 Operating System Software. Even for just me there is no single best OS X. Two Macs (2017 iMac and 2011 MacBookPro) with SSD drives are running High Sierra because it is the latest release. An iMac (2014) runs Sierra because it has a Fusion drive and there is no APFS sup.
The version of macOS that came with your Mac is the earliest version compatible with that Mac. To find out whether your Mac is compatible with a later version of macOS, check the system requirements: How to join your friends game in gmod.
If your Mac won't start up from a compatible version of macOS, it might require a specific build of that version. To get the correct build, reinstall macOS or upgrade to a later version of macOS.