Board #1 is the Full version. All the twelve switches are connected separately to their own pins on the headers. Twelve pins on the top and twelve pins at the bottom.
Board #2 is the Matrix version. The switches are connected in a 3×4 matrix with the four rows and three columns connected to the header on the bottom. The small headers close to the top is not connected anywhere and only there for making the board sit stable to the breadboard.
Board #3 is the Analog version. The switches are connected to a resistor voltage divider that have an analog output ranging from VCC to GND. Easy to hook up to and decode on an ADC pin on a microcontroller. The headers at the bottom is GND/Out/Vcc. The headers close to the top is connected anywhere and only there for making the board sit stable to the breadboard.
The white dots are for labeling the buttons for your own project. 0-9 and *# might not be optimal for every project you do, so I thought it would be better to just leave the labelling to the user.