How does the sea and river separated?

Seas and rivers are two different types of water bodies and they are not physically separated from each other. While both contain water, seas are part of the ocean and are found along the coastline, while rivers are freshwater bodies that flow from inland areas towards the sea or ocean. Rivers eventually merge with the sea, forming estuaries where freshwater and saltwater mix. Therefore, it is not accurate to state that the sea and river are separated.