Atomic physics as a part of physics deals with the study of atoms and its components, which are neutrons, electrons and protons. The field is primarily focused on the presence of electrons in the atom, their arrangement and the processes, which can change this arrangement. This field is also closely related to molecular, atomic and optical physics. The aim of this book is to present these topics in the most easy to comprehend language. It attempts to understand the multiple branches that fall under the discipline of atomic physics and how such concepts have practical applications. This textbook is an essential guide for both academicians and those who wish to pursue this discipline further.