Why does variation exists in the temperature, density, and salinity of ocean water?

In order to heat a substance up, you need to h have a light source. For the ocean, the sun is the light source. The Earth is not like a perfect round ball, so it is further stretched out on the sides. This stretched out side is along the center of the Earth (the equator). This means that the equator is closet to the sun and the ocean along the equator is the warmest.

The density of the ocean is simply how hard or soft the ocean is. As you know, ice is harder than water with no ice. This is because of tiny particles known as atoms. Think of it like this: you come back from Mount Everest and you have hot coffee and you are excited, so you run around. If you have cold milk, you are less likely to