What is the reason for the strong heating and combustion of artificial earth satellites when entering

What is the reason for the strong heating and combustion of artificial earth satellites when entering the dense layers of the atmosphere?

Friction is the main reason for the heating and subsequently the combustion of artificial satellites when passing through dense layers of the atmosphere. Friction of the body against atmospheric molecules occurs. Since the density of the atmosphere is high, the number of molecules that the body rubs against is also large. The kinetic energy of the satellite begins to pass into the internal energy of the body, it heats up very much and then burns out as a result of the high temperature.