What is the relationship between temperature and thermal energy?

Temperature is the amount of heat in degrees the object has. Heat is what is given of from thermal energy. Thermal energy is what is given off when energy is lost. Because according to the Law of Conservation of Energy: Energy can neither be created nor destroyed, but transferred to a lesser form.

"As the air becomes warmer, heat is transferred between molecules and kinetic energy is created which produces thermal energy. As the molecules move faster to transfer heat, the temperature also increases ".

-Quora

As we know when temperature increases the molecules, the particles speed up. This makes potential energy decrease and because of that kinetic energy increases. Overall when the temperature goes up, thermal energy goes up, that leads to an increase in kinetic energy.