How to find the Linux Distro Name and version

Some distros put a '*-release' or '*-version' file 
in /etc. Here are some examples: 

/etc/redhat-release 
/etc/debian_version 
/etc/SuSE-release 
/etc/slackware-version 
/etc/gentoo-release 

You could do 'cat /etc/*-release' or 'cat /etc/*-version'.