This textbook was written with two primary objectives. The first is to introduce the Java programming language. Java is a practical and still-current software tool; it remains one of the most popular programming languages in existence, particularly in areas such as embedded systems. Java facilitates writing code that is very efficient and powerful and, given the ubiquity of Java compilers, can be easily ported to many different platforms. Also, there is an enormous code-base of Java programs developed, and many systems that will need to be maintained and extended for many years to come. The second key objective is to introduce the basic concepts of OOPs.