Short description Unable to find a suitable coursebook for an introductory PDE course, the author wrote one that combines the needed foundation and theory with tangible applications in physics and other disciplines. Since many practical applications are non-linear, numerical solution techniques are required. Consequently, the book introduces this topic in a general way before providing the necessary details. As for an introduction to a specific method, the finite difference method is the natural place to begin. With this approach, readers more clearly understand the notations of order and convergence as well as explicit and implicit methodologies.