Question

What is meant by vertical shift and lateral shift

Answer 1

vertical shift and lateral shift are physical terms.
lateral shift :the distance between parallel rays
vertical shift: the distance between two points of a perpendicular drawn to a glass slab

Answer 2

Distance between emergent ray and divergent ray is known as vertical shift.
whereas
When light rays travel across two parallel surfaces, the emergent rays from the second surface are parallel to the incident rays on the first surface.The perpendicular distance between them is called the lateral shift.

           Hope it helps...!!!
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