What is Classical Physics and what subjects It Deal with?

Mechanics - We study Newton's laws of motion under mechanics.

Electrodynamics - It deals with the magnetic and electric phenomena associated with the magnetic and charged bodies.

Thermodynamics - It deals with the macroscopic equilibrium systems and is concerned with internal energy changes, entropy, temperature, and more, of the system via the transfer of heat and external work. The efficiency of heat engines and refrigerators and more.

Optics - The study of phenomena connected with light and optical instruments such as microscopes, telescopes, and more related things.