In electronics and telecommunication, coupling is the desirable or undesirable transfer of energy from one medium, such as a metallic wire or an optical fiber, to another medium.
Coupling is also the transfer of electrical energy from one circuit segment to another. For example, energy is transferred from a power source to an electrical load by means of conductive coupling, which may be either resistive or hard-wire. An AC potential may be transferred from one circuit segment to another having a DC potential by use of a capacitor. Electrical energy may be transferred from one circuit segment to another segment with different impedance by use of a transformer. This is known as impedance matching. These are examples of electrostatic and electrodynamic inductive coupling.
Coupling (electronics) Wikipedia
Electromagnetic induction:electrodynamic -- commonly called inductive coupling, also magnetic coupling
electrostatic -- commonly called capacitive coupling
evanescent wave coupling
Electromagnetic radiation:radio -- wireless telecommunications
electromagnetic interference (EMI) -- Sometimes called radio frequency interference (RFI), is unwanted coupling. Electromagnetic compatibility (EMC) requires techniques to avoid such unwanted coupling, such as electromagnetic shielding.
Microwave power transmission
Other kinds of energy coupling:acoustic