What affect does a large body of water have on climate of a nearby landmass?

Oceans moderate the temperatures of nearby land because water heats and cools much more slowly than land. Therefore, winds coming from the ocean usually deter hot or cold extremes in coastal regions like California, Florida, and other states. However, places toward the center of a country or continent will often have these hot and cold extremes during summer and winter. This occurs because they are secluded from the oceans and do not get the moderated weather from the oceans.