aircraftcockpit
Traditionally, an aircraft can either run on electricity or can be powered by combustion engines internally. Both will have some electronic components but more will be found in electric aircraft. In a traditional aircraft (combustion engine) the syncing and maintenance of these components is paramount as safety is a constant issue within aircrafts. Most aircrafts will have transformer rectifiers, as the name suggests transforms the voltage from what comes in to what the aircraft requires to run properly. Most aircraft run on an AC main electrical system but the transformer will act as the electrical component that will convert and power DC components in the aircraft.
Most aircraft with an AC main electrical system will also have a constant speed drive.
The point of this electronic component is that is makes the power flow constantly rather than in a fluctuating way as you would see typically coming from an engine. Imagine when you drive a car you will hear the engine working, sometimes it works harder than other times. In an aircraft the speed needs to be fairly constant, the constant speed drive deals with the power from the engine making it constant and resulting in a smooth flight.