A semiconductor device which produces light when an electric current flows through it is called LED or Light Emitting Diode.
A device which emits light by the optical amplification using stimulated emission of electromagnetic radiation is called LASER.2 sept. 2022
A number of studies have been completed that compared the effectiveness of laser light to LED light and the majority have found laser light to be far more effective, particularly in treating tissue of any significant depth.
A regular diode is a semiconductor device that works as a one-way switch for electrical current.
It allows current in only one direction and will stop it from flowing in the other.
An LED works the same way.
The only difference is that it emits light when the current passes through, as the name suggests.