Kittel focuses on the macroscopic thermodynamic properties of materials, while Schwabl's approach is more microscopic and considers the behavior of individual particles.
Kittel's "Introduction to Solid State Physics" is often recommended for beginners, as it provides a thorough introduction to the fundamentals of thermal physics.
Both Kittel and Schwabl's books cover the basic principles of thermal physics, such as the laws of thermodynamics and statistical mechanics.
Schwabl's "Statistical Mechanics" is considered to be more mathematically rigorous, as it delves into the mathematical foundations of thermal physics.
While both books cover the basics of thermal physics, Kittel's book also includes chapters on magnetism and superconductivity, while Schwabl's book focuses more on quantum mechanical aspects of thermal physics.