How to check Linux Version - LinuxConfig.org

The common scenario is that you have been given an access to a Linux system physically or via remote login and you have no idea what Linux version is installed on this particular system. Given that many of the today's Linux Distributions have implemented systemd as part of their core design, to check for a Linux version is in many cases relatively simple procedure.
This is a companion discussion topic for the original entry at https://linuxconfig.org/how-to-check-linux-version