Why are the oceans salty and how does it vary between large water bodies

The Oceans are saline or salty because of the several natural occurrences. One of the reason is the rivers because it brings water with minerals by crossing over soil and stones, moving salt along the way, which adds into the oceans, results in salinity by evaporating the water.

Ocean salinity levels can change from place to place. The Mediterranean Sea is saltier. The Atlantic Ocean has access to the freshwater rivers, such as the Amazon which provide less salinity in the ocean.