The document discusses heat transfer during phase changes. It defines specific heat as the heat required to change an object's temperature, and latent heat as the heat required to change an object's phase, such as from solid to liquid. Latent heat of fusion is the energy required for melting/freezing, while latent heat of vaporization is for boiling/condensing. Two examples problems are included to calculate the energy required to melt silver and the amount of water that remains unfrozen given a specific heat transfer.