Transverse Waves

Here is a transverse wave; the oscillations are perpendicular to the direction of propagation.

Where the particles are displaced above the equilibrium position we call a peak and below we call a trough.

The wavelength is the distance from one peak or trough to the next.

The amplitude is the maximum distance the particle moves from its equilibrium position up or down.

Examples: water waves,

Mexican waves and

waves of the EM spectrum

EM waves are produced from varying electric and magnetic field.