As you can see from the above, you get the full version (major and minor release numbers – 9.4) plus the distributor ID (Raspbian) and the current major release codename: stretch (this codename is usually specified in /etc/apt/sources.list file to be used by the apt tool).
Finally, if you were looking for the Linux kernel information, just use uname -a:
I'm a principal consultant with Tech Stack Solutions. I help with cloud architectrure, AWS deployments and automated management of Unix/Linux infrastructure. Get in touch!