Imagine water in a kettle, as you wait for it to boil. A lot of energy is transferred from the heat source to the water in the kettle, and it takes a long time for the water to boil. This is due to the very high specific heat capacity of water. When compared with a similar amount of air, significantly more energy is required to heat a given amount of water.

Just like the water in your kettle, ocean water has a high heat capacity. The oceans can hold and transfer immense amounts of heat energy all around the globe, which has a profound impact on the global climate.