Evaporation and boiling
Evaporation and boiling are two different modes of phase transitions from liquid to gas. We will take water as an example. Evaporation occurs at the surface of water. Evaporation is an adiabatic process. Evaporation uses its internal energy to supply energy for phase transition. In evaporation, the water cools post its supply of energy for phase change. The energy that goes to change phase at constant volume ( no work) is called latent energy or latent heat. This is called latent heat because primarily it is the potential energy of the substance hidden in the intermolecular bonds of the substance. You can't feel this energy in a substance and hence it is called latent heat. Since evaporation uses its internal energy, evaporation can occur as long as a substance possesses internal energy. Internal energy is the sum of kinetic + potential energy and stays in a substance until a substance reaches - 273,15 degc. Theoretically even at - 273.15 degc, called absolute temperature a substance still carries zero point point energy inside the atoms where the electrons still go up and down the energy level.
Let's come to boiling. In boiling the phase transition occurs by a different process. Boiling takes place by isothermal heat transfer process at constant temperature and pressure. Here, the energy for phase change or breaking H bond comes from the external supply of heat. Water is a cluster of H-bonded molecules with stored potential energy. The external supply of heat breaks these bonds. This external energy is the latent heat. Once bonds break water expands 1600 times and transforms into steam. Boiling always occurs at the saturation temperature of the prevailing pressure. Only at the saturation temperature and corresponding pressure, do all H bonds break.
In summary, both evaporation and boiling involve phase change. Evaporation uses internal energy. It can occur until there is internal energy in a substance which is absolute zero temperature. Boiling occurs by the isothermal heat transfer process. Boiling occurs only at saturation temperature and saturation pressure that can break H bonded clusters of water molecules.