Here's a quick post on how to identify your Raspberry Pi version from the shell. There's also a list here.
These shell commands will display the unique CPU id, hardware and revision level of your Pi. I also have a script that will print your Pi model in plain text.
CPU=`cat /proc/cpuinfo | grep Serial | cut -d ':' -f 2 | sed -e "s/ //g"` HW=`cat /proc/cpuinfo | grep Hardware | cut -d ':' -f 2 | sed -e "s/ //g"` REV=`cat /proc/cpuinfo | grep Revision | cut -d ':' -f 2 | sed -e "s/ //g"` echo CPU: $CPU, HW: $HW, REV: $REV
And here's a table of the revision codes to date:
[table]
Model & Revision,Revision Code
Pi 3 Model B,a22082
Pi Zero,900092
Pi 2 Model B,a21041
Pi Model A+,0012
Pi Model B+,0010
[/table]