This book provides an introduction to quantum field theory (QFT) at an elementary level, with only special relativity, electromagnetism, and quantum mechanics as prerequisites. For this fresh approach to teaching QFT, based on numerous lectures and courses given by the authors, a representative sample of topics has been selected, containing some of the more innovative, challenging, or subtle concepts. They are presented with a minimum of technical details, with the discussion of the main ideas being more important than the presentation of the typically very technical mathematical details necessary to obtain the final results. Special attention is given to the realization of symmetries in particle physics: global and local symmetries, explicit, spontaneously broken, and anomalous continuous symmetries, as well as discrete symmetries. Beyond providing an overview of the standard model of the strong.