Software engineering is the systematic application of engineering approaches to the development of software.[1][2][3][1][4][5]

Notable definitions of software engineering include:

"the systematic application of scientific and technological knowledge, methods, and experience to the design, implementation, testing, and documentation of software"—The Bureau of Labor Statistics—IEEE Systems and software engineering - Vocabulary[6]

"The application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software"—IEEE Standard Glossary of Software Engineering Terminology[7]

"an engineering discipline that is concerned with all aspects of software production"—Ian Sommerville[8]

"the establishment and use of sound engineering principles in order to economically obtain software that is reliable and works efficiently on real machines"—Fritz Bauer[9]

"a branch of computer science that deals with the design, implementation, and maintenance of complex computer programs"

The term has also been used less formally:

as the informal contemporary term for the broad range of activities that were formerly called computer programming and systems analysis;[10]

as the broad term for all aspects of the practice of computer programming, as opposed to the theory of computer programming, which is formally studied as a sub-discipline of computer science;[11]

as the term embodying the advocacy of a specific approach to computer programming, one that urges that it be treated as an engineering discipline rather than an art or a craft, and advocates the codification of recommended practices