Solids, liquids, and gases are the three most common states of matter. A sample of matter typically exists in one of these three states. Yet heating, cooling, and/or changes in pressure can cause the sample to change from one state to another state. The transitions or changes between states are processes that have specific names.

Solids and Liquids
The state change from a solid to a liquid is known as melting (or fusion). The state change from a liquid to a solid is known as freezing.

Liquids and Gases
The state change from a liquid to a gas is known as vaporization. The state change from a gas to a liquid is known as condensation. Vaporization can occur at any temperature. When it occurs at the so-called boiling point temperature, we also refer to the process as boiling. When vaporization occurs below the boiling point temperature, we refer to the process as evaporization. 

Solids and Gases
The state change from a solid to a gas is known as sublimation. The state change from a gas to a solid is known as deposition.