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.
Ocean currents are also very important in the dispersal of many life forms. An example is the life-cycle of the European Eel. Ocean currents are important in the study of marine debris, and vice versa. These currents also affect temperatures throughout the world.