Comparing Uno with Leonardo some paragraphs state the differences. On the quoted paragraph it should say Leonardo instead of Uno. Uno has 14 Digital pins not 20.
Input and Outputhttp://arduino.cc/en/Main/ArduinoBoardLeonardo
Each of the 20 digital i/o pins on the Uno can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. In addition, some pins have specialized functions:
This for beginners (me) don't get confused.
New Leonardo looks good!