Domestic devices get their energy from two main sources. A battery has energy stored in a chemical store, and it transfers this to the circuit when the device is switched on. Mains electricity is an alternating current (a.c.), and it transfers energy to anything plugged into a socket.
In a heating device such as a kettle, the heating element transfers electrical energy as thermal energy to the water. This is the useful transfer. Some thermal energy also heats the kettle itself and the surroundings, so that part is wasted.
In a motor, such as in a drill or a toy car, electrical energy is transferred to kinetic energy. Energy is wasted because the wires resist the current and heat up, and because friction between moving parts transfers thermal energy. Some energy is also wasted as sound.