Ocean and sea both are water bodies. Ocean is the water body that contains heavy percentage of earth's water. Sea is the salt water that covers areas less than oceans. Seas are usually located near the land while the same is not necessary for oceans. Aquatic life is possible in sea while oceans supports aquatic life in limited way. There is a large quantity of marine life in the Seas but the marine life in oceans is usually confined to bacteria, shrimp, microscopic planktons. The largest sea is Meditteranean Sea with 1.14 million square miles and the largest ocean is Pacific ocean with 60 million square miles.
Both sea and oceans are water bodies and both have salty water.The major difference between them is that sea is smaller compared to the ocean and Sea is partly connected to land.When one look at an ocean there is no end to it, it’s a wide expanse of water. Sea is actually located where the land meets the ocean.As the sea is closely connected to the land the environment of the sea is more suitable for marine animals and plants.We find more of these in sea than in oceans.