The three ways that heat is transferred are as follows: Conduction, convection, and radiation. Radiation is when heat is transferred in waves. It is the only type of transfer that can occur in a vacuum, so that is how heat reaches earth from the sun. Conduction is when heat is transferred between solid objects. That is how heat is transferred between objects on the earths surface. Convetsion is when heat is transferred through a liquid. This is how the ocean heats all the way through, rather than just the surface.
Water's polarity makes it an excellent solvent for salts, like sodium chloride, as other substances required by cells to carry out metabolic processes.
