How is temporal coherence key of characteristics of laser?

Temporal coherence:

This coherence is a measure of the correlation among the phases of a light wave at various points along the direction of propagation. This coherence tells us what and how monochromatic a source is.

Measurement of temporal coherence in terms of coherent time is as follows:

Coherent time = Coherent length/ Velocity of light.

There coherent time is the indication of the total time in that the wave passing from any point is continuous.