Marine regression means that, submerged sea floor are exposed. It exposes the sea bottom while the transgression may result into flooding. A sea level transgression or marine transgression means when the water level or sea level arises in land, it also means that the sea level will move towards higher land.
Transgression is when the sea-level rises, pushing the coast line inland. Regression is the sea-level falling, pushing the coastline out towards the ocean.
