The name Schuko is derived from the German 'Schutzkontact" meaning "protective contact" a reference to the clip-shaped earth contact in contrast to the pin-type earth contacts used in other formats.
The Schuko plugs and sockets are considered safer as they are totally enclosed and the pins cannot be accessed as long as the plug is not taken out of the socket.
The earthing lead is connected through a clip which ensures that the earthing lead makes contact before the phase and neutral leads.
The Schuko sockets can also accept C type plugs.