Difference Between Sea and Lake (with Table)

For the times immortal, water has been an essential part of the survival of all kinds of living beings may it be animals, plants or humans. Water is the key to life on our planet. Without the existence of water, any of the living beings can not survive. Of all the area of the planet Earth, about 71% is water.

Water being an essential part of survival exists in various kinds of water bodies. Some of the different types of water bodies are Ocean, Sea, River, Lake, Lagoon, Pond, Reservoir, etc, where oceans hold about 96.5% of the total water on Earth. 

Sea vs Lake

The main difference between a sea and a lake is that a sea is a larger water body that holds a great amount of water in it and is usually deeper, the seawater is usually saltwater, on the other hand, a lake is small to moderate in size and has a lesser amount of water as compared to a sea, it is also shallower than the sea, the water of the lake can either be freshwater or salty.

The two important water sources for human beings are seas and lakes. Sea is a large water body that holds a great amount of water and is deeper. A sea is not enclosed by land on sides, however, there exist some exceptions to this. There are seas present on the Earth that are landlocked. Another important water body is a lake which is a landlocked water body. Lakes are usually moderate in size and are much shallower than the sea.

Comparison Table Between A Sea and A Lake

Parameter of Comparison




A sea is a water body that is usually not enclosed by land on its sides, it is home to a saline water ecosystem.

A lake is a smaller water body that is enclosed by land on all its sides, it is home to a large number of aquatic creatures.

Formation and ecosystem of the body

A sea is a naturally formed water body, that provides a home to large saline water ecosystems.

A lake is either natural or man-made, it is sometimes formed by separating from large water bodies. A lake is home to important aquatic ecosystems.

Size and depth

A sea is a large water body and has usually a greater depth.

A lake is much smaller as compared to a sea and is also shallower.

Type of water

A sea contains salty water.

A lake has either freshwater or saltwater.


Caribbean Sea, Bering Sea, Mediterranean Sea, The Sea of Japan, Andaman Sea, etc.

Pangong Tso Lake, Lake Baikal, Caspian Sea, Dead Sea, Lake Superior, Lake Erie, etc.

What is the Sea?

A sea is a naturally formed water body and is a perennial source of water. A sea is a water body that is not surrounded by land on all its sides. A sea is a large and deep water body. It is a body that takes its water to the oceans through bays or straits. A sea acts as a home for a large number of large ecosystems, these ecosystems involve thousands of organisms in it.

The seawater is usually salty to taste. A sea plays a significant role in maintaining the climate on Earth. It also regulates the carbon and nitrogen cycles of Earth. However, overfishing and the increased levels of carbon dioxide have left the sea ecosystem drastically affected.

The sea also plays an important role in marine trade, power generation, mineral extraction, etc. They act as ports and dockyards. Some of the examples of seas in the world are The Mediterranean Sea, The Caribbean Sea, The Sea of Japan, the Andaman Sea, the Baltic Sea, the Black Sea, etc.