Sometimes you need to know what version of the Operating system is installed on your server. This is extremely useful when you order a dedicated server and want to know what is the version of OS on it. A simple command will help you as usual:
cat `ls /etc/*{-,_}{release,version} 2>/dev/null | head -n 1`
This will show you something like
The picture below shows the difference between common commands: one shown above and uname -a. Sometimes you don’t need the kernel version, just the operating system name. This command should help you to do that.