Question

difference between coastal [plains and plains

Answer 1

A coastal plain is an area of flat, low-lying land adjacent to a seacoast.

a plain is a flat area.

Plains occur as lowlands and at the bottoms ofvalleys but also on plateaus or uplands at high elevations.

Answer 2

Coastal plains - low elevation & low relief.
                       - lie along the shore.
Plains - varied elevation & low relief.
           - surrounded by other land.