Physics

Physics is a branch of science that deals with the study of matter, energy, and the interactions between them. It seeks to understand how the natural world behaves at the most fundamental level. Physicists study everything from subatomic particles to the structure and evolution of the entire universe.
The principles of physics are used to explain a wide variety of phenomena, including the behavior of light and sound, the behavior of materials under stress and strain, the properties of magnetic and electric fields, and the behavior of matter at extremely high or low temperatures. Many of the technologies we use today, such as computers, cell phones, and medical imaging devices, rely on principles of physics.
Some of the major areas of study within physics include classical mechanics (the study of motion and forces), electromagnetism (the study of electric and magnetic fields), thermodynamics (the study of heat and temperature), quantum mechanics (the study of subatomic particles), and astrophysics (the study of the universe).
The tools of physics include mathematical models and equations, laboratory experiments, and observations of natural phenomena. Physicists use these tools to develop theories and test them against experimental data. The process of developing and refining these theories is a central part of the scientific method.
In addition to its practical applications, physics also plays an important role in shaping our understanding of the world and our place in it. It has led to groundbreaking discoveries about the nature of matter and energy, the structure of the universe, and the behavior of the natural world.
A lot of sub-disciplines in physics fall under the broader fields of classical mechanics, electromagnetism, thermodynamics/statistical mechanics, and quantum mechanics. These four fields are often referred to as the "core" or "fundamental" areas of physics, and they provide the foundation for much of modern physics research.

Classical Mechanics

Electrostatics

Magnetostatics

Electrodynamics

Electromagnetic waves

Optics

Quantum electrodynamics


Classical thermodynamics

Statistical thermodynamics

Chemical thermodynamics

Engineering thermodynamics

Non-equilibrium thermodynamics

Quantum mechanics