Answer: True
Refraction is a phenomenon in which the light bends or changes its direction (and changes the speed of propagation, as well) <u>when passing through a medium</u> with a refractive index <u>different from the other medium. </u>
Where the Refractive index is a number that describes how fast light propagates through a medium or material:
Being a relation between the speed of light in vacuum
and its speed in the other medium
.
It is important to note that in this process, the wavelength may be modified because it depends on the medium, however, the refracted ray of light does not change its frequency.