This book presents in a self-contained form the typical basic properties of solutions to semilinear evolutionary partial differential equations, with special emphasis on global properties. It considers important examples, including the heat, Klein-Gordon, and Schroödinger equations, placing each in the analytical framework which allows the most striking statement of the key properties. With the exceptions of the treatment of the Schroödinger equation, the book employs the most standard methods, each developed in enough generality to cover other cases. This new edition includes a chapter on stability, which contains partial answers to recent questions about the global behavior of solutions. The self-contained treatment and emphasis on central concepts make this text useful to a wide range of applied mathematicians and theoretical researchers.