A programming language is a scientific language that comprises a set of instructions producing various kinds of output. Programming languages are essential in computer science and are used in computer programming to implement algorithms. Programming language theory is a branch of computer science that is concerned with the design, implementation, analysis, characterization, and classification of programming languages and of their individual characteristics. Java, Python, C, Ruby, Javascript, C#, and PHP are some of the prominent programming languages. They are used for front-end web development, back-end web development, desktop application, mobile development, and game development. The topics included in this book on programming languages are of utmost significance and bound to provide incredible insights to readers. There has been rapid progress in this field and its applications are finding their way across multiple industries. This book is a resource guide for experts as well as students.