Switches can be of two categories:
Unipolar, interrupt only one of two cables (or phase or neutral) by opening or closing the circuit. You have to be careful because with this type of circuit breaker the current can still reach the lamp or the appliance because if you do not interrupt the phase cable you can still take the shock.
Bipolar, interrupt both cables, this is the type of switch on the counter and switches on the main power board lines.
The deviators appear to be normal circuit breakers but do not actually interrupt the circuit by disconnecting the current but diverting it from one line to another.