Java is a programming language that is specifically designed to have minimal implementation dependencies. It is built as an object-oriented language. Its syntax is largely influenced by C++. Java applications are compiled to bytecode. They run on any Java virtual machine. It is the most widely used language for Client-Server web applications. It plays a crucial role in mobile operating systems. This book is a compilation of chapters that discuss the most vital concepts in the field of Java. It is compiled in such a manner, that it will provide in-depth knowledge about the techniques of computing and programming with Java. In this book, constant effort has been made to make the understanding of the difficult concepts of Java programming as easy and informative as possible, for the readers.