Melting is the change of phase from a solid to a liquid. Solidification , or freezing, occurs when a liquid turns into a solid. We call the change freezing when the temperature at which the liquid turns into a solid is fairly low. We normally don't imagine metals as freezing when they turn solid at temperatures of several hundred degrees on the Celsius scale. In this case we would say they solidify.
Vaporization occurs when a liquid changes into the gaseous state.
Condensation is the reverse process, when a gas changes to the liquid state. Occasionally a solid may not go through the liquid phase before it enters the gaseous state. Sublimation is the process of converting a solid directly to a gas. Sublimation occurs when solid carbon dioxide, dry ice, absorbs enough heat at standard atmospheric pressure. This sublimation is often used in theaters to produce the appearance of fog without having to boil a liquid to produce a vapor.