Quotation marks, also called 'inverted commas', are of two types: single and double. British practice is normally to enclose quoted matter between single quotation marks, and to use double quotation marks for a quotation within a quotation:
The oceans absorb the sun's heat, transferring it to the atmosphere and distributing it around the world via the ever-moving ocean currents. This drives global weather patterns and acts as a heater in the winter and an air conditioner in the summer.
at the surface and beneath currents gyres and eddies play a crucial role in physically shaping the coasts and ocean bottom in transporting and mixing energy chemicals and other materials within and among ocean basins and in sustaining countless plants and animals that rely on the oceans for life including humans