This is Light of which all parameters are predictable and correlated at any point into time or space, particularly over an area perpendicular to the direction of propagation or over time at a particular point in space. Simply, coherent light usually refers to the phenomenon relating to the existence of a correlation between the phases of the corresponding components of two light waves or to the values of the phase of a given component at two instants in time or two points in space. Coherent light does not occur naturally in the Universe. It can only be generated in a laser.