Characteristics of Lasers

Laser light has three unique characteristics, that make it different than "ordinary" light. It is:

• Monochromatic
• Directional
• Coherent

Monochromatic means that it consists of one single color or wavelength. Even through some lasers can generate more than one wavelength, the light is extremely pure and consists of a very narrow spectral range. Directional means that the beam is well collimated (very parallel) and travels over long distances with very little spread.
Coherent means that all the individual waves of light are moving precisely together through time and space, i.e. they are in phase.