Emission is a word that originally comes from Latin. Originally it means something that is sent out. Several things can be sent out:
- The most common use talks about emission of toxic gases. Those gases get produced by factories and motors, like motors in cars.
- People talk about radio emissions. Those are programmes that people can listen to if they have a radio receiver.
- There could be emissions of loud noise, someone might be making loud noises.
- There also are emissions of light.
Emission Facts for Kids. Kiddle Encyclopedia.