Aircraft electrical system

 The electrical system generates, distributes and protects electrical power to all the aircraft systems.

This includes lights, radios, some anti-ice components and in some cases flight controls such as flaps dependeing of the specific design.

Some systems are electro pneumatic (electrically activated, pneumatically operated) and others are electro hydraulic (electrically activated and hydraulically operated).

As you can see the electrical system is among the most important systems in any aircraft.