Beaches are perhaps the most obvious landform built by coastal erosion. Not only does the wave action break down shoreline rocks into ever smaller particles that we recognize as sand, but it also carries sand up from the ocean and deposits it on the land. Though scientists would describe the beach to encompass an area inland to include dunes and stretching out into the water where formations might be present, most tourists are concerned with the active sandy area where sand meets water.
As sea erosion works against the shore, beaches are not the only resulting landforms. Headlands and bays are also created. A bay is where the rock material comprising the shoreline is softer and more susceptible to erosion, while headlands refer to the harder rocks that do not wear away as easily. Looking at a map, a bay is a circular area that appears to have been scooped out of the coastline. It provides a protection of sorts for certain plant and animal life as well as boats. A headland resists erosion and can be seen as a point that juts into the water.
Coastal cliffs are normally formed when waves undercut the land material until it collapses, leaving a sheer face standing above the water. Examples of this can be seen in the United States all along the West Coast and also in Maine. Cliffs form the foundation from which many other landforms eventually arise as the water continues its eternal erosive process. For a look at what some would call the most spectacular cliffs in the world, some very nice photos of the White Cliffs of Dover can be found on Flickr.
As cliff formations erode away, other landforms begin to take shape, first sea caves and then arches, stacks and stumps. There are some very good examples of these on the California coastline which, by the way, makes for a beautiful drive. As the water undercuts a newly created cliff, sea caves form underneath, perhaps not even visible from outside but reachable by diving beneath the water. As the caves widen and run together, parts of the cliff collapse, leaving magnificent arches sticking out in the ocean. Continuing erosion eventually causes the arches to collapse, leaving stacks and stumps as the lone remnants of the cliff.