Conduction is the transfer of heat through a material without the movement of the material itself, typically occurring in solids.

Convection is the transfer of heat by the movement of fluids (liquids or gases) due to differences in temperature and density.

Radiation is the transfer of heat in the form of electromagnetic waves, such as infrared radiation, which can occur in a vacuum.

An ice cube melting in a person’s hand is an example of conduction.

Warm air rising near the ceiling of a room is an example of convection.

The heat from the sun warming the Earth is an example of radiation.

Warm air rises because it is less dense than cooler air.

In convection, warmer, less dense fluid rises while cooler, denser fluid sinks, creating a current.

Heat flows from the warmer water to the colder ice, causing the ice to melt.

Thermal equilibrium is the state in which two objects in contact no longer transfer heat, as they are at the same temperature.