So philosophy is not science, religion, or art. It is its own thing. Epistemology is the study of knowledge. Ethics is the study of right and wrong in human action. Aesthetics is the study of beauty.
Logic is the study of the principles of right reasoning.
Logic is the basic tool that philosophers use to investigate reality. These are the main branches of philosophy. Throughout its history, however, the discipline of philosophy has also been used as a tool to investigate other domains of life.