Difference between thermal energy and heat?

Answer 1

They are the same. Temperature is a measure of "sensible" heat. Latent heat is heat which produces a change in state with no change in temperature. Sensible heat is heat that produces a change in temperature without a change of state. Heat, heat energy, and thermal energy are the same thing, it is measured in Joules, calories or British Thermal Units (btu).

Example: Placing a hot object in ice (at the freezing point), the object gives up heat to the ice causing the ice to melt, the temperature of the object decreases to the temperature of the ice, the ice melts, changes state, until the object reaches the temperature of the ice and water. The heat given up from the object affected it's sensible heat (temperature), the heat absorbed by the ice changed it's state, latent heat, but not it's temperature or the temperature of the liquid water. This is an exchange of thermal energy from a high energy state to a lower energy state.

Another Answer

The term, 'thermal energy' is obsolete. It has long been replaced with the term, 'internal energy'.

Internal energy and heat are different.

Internal energy is the sum total of all the energies associated with the vibration of the molecules/atoms that form a body.

Heat is energy in transit from a warmer body to a cooler body. Heat is closely associated with work, which is energy in transit from one form into another. The differencebetween work and heat represents the change in a body's internal energy.