What is impedance in waves?

Impedance in waves refers to the measure of how much a medium resists the propagation of a wave through it. In the context of mechanical waves, such as sound, it is defined as the ratio of pressure to particle velocity. In electromagnetic waves, impedance can be characterized by the ratio of electric field to magnetic field strength. Impedance plays a crucial role in determining how waves reflect, transmit, or absorb at boundaries between different media.