The molecules of all material substances are always in continuous motion. They can be in vibration or agitation due to the multiple interactions they undergo within the body.
As a consequence of this random agitation, the atoms and molecules of matter have specific internal energy since they have kinetic energy in the form of movement. They also possess potential energy due to the forces exerted between the particles.
Internal energy is also known as the thermal energy of bodies.
On the other hand, the temperature is the magnitude that allows the average value of a body’s thermal energy to be recorded.
The specific heat is the amount of heat necessary to change 1.00 kg of mass by 1.00 ºC.