Software is the collection of data and instructions that drives the working of the computer. Software is usually written in high-level programming languages, which are then translated into machine language via a compiler or interpreter. Computer software can be classified into application software, system software and malicious software. The development of software through the application of scientific and technological methods is under the scope of software engineering. It is a vast subject that branches out into a number of significant sub-domains such as software requirements, software design, software testing, software construction, software development process, etc. This book explores all the important aspects of software engineering in the present day scenario. It is an upcoming field that has undergone rapid development over the past few decades. For all those who are interested in this domain, this textbook can prove to be an essential guide.