Crests: In transverse wave, the points where the particles of the medium have maximum displacement in the positive direction are called crests. It means the highest part of a wave. In Fig., points A and E are crests.
A crest is the point on a wave with the maximum value or upward displacement within a cycle. A crest is a point on the wave where the displacement of the medium is at a maximum. So we can say that a crest is a point on the wave where the displacement of the medium is at a maximum.
