Introduction to Causal Fermion Systems

This paper is dedicated to give a concise introduction to the theory of causal fermion systems. After putting the theory of causal fermion systems into the historical context, we recall fundamental physical preliminaries. Afterwards, we enter the underlying ideas of the principle of the fermionic projector and clarify its connection to causal fermion systems. We finally outline the main structures of the theory of causal fermion systems.