Explain the difference between laser light and light from an incandescent bulb?

Question

festinger · Answer

The light from a laser light has only one wavelength, whereas the light from the incandescent bulb is emitted over a whole spectrum of wavelengths.

The light from laser light is also collinear, which means that it doesn't spread that much.

festinger · Answer

I also forgot to mention that laser light is coherent. Coherence is the degree of correlation between the wave and its delayed copy. It's like how in phase the 2 copies of light wave are.