There are two main types of vaporization:

* Evaporation: This occurs at the surface of a liquid, where molecules with enough kinetic energy escape into the gas phase. It happens at any temperature.

* Boiling: This occurs when the vapor pressure of the liquid equals the surrounding atmospheric pressure. It happens at a specific temperature called the boiling point.

Both processes involve the absorption of heat energy, which gives the liquid molecules enough energy to overcome the intermolecular forces holding them together and transition into a gas.