This work introduces students to the amazing and impressive expanse of propulsion systems used in aeronautics and aerospace, ranging from the piston engine and propeller to the rocket. Many examples and problems are included to illustrate the principles common to all propulsion types. Through this approach, students can develop an understanding of the reasons for trends and limitations in design and performance as well as explore the similarities between the types. Intended for use as an undergraduate text, this work should also be a useful reference for practising engineers.