explin software engineering?

Answer 1

Software Engineering (SE) is the design, development, and documentation of software by applying technologies and practices from computer science, project management, engineering, application domains, interface design, digital asset management and other fields.

Refer for more info: http://en.wikipedia.org/wiki/Software_engineering

Answer 2

The goal of software engineering is to be discipline that provides models and processes that lead to the production of well documented maintenable software in a manner that is predictable. For a mature process it should be possible to determine in advance how much time and effort will be required to produce the final product. This can only be done using data from past experience which requires that one measure the software process.
Software Engineering also calls for the ability to make precise specifications of the behaviour of software systems. Several methods exist for doing this. Algebraic specification uses formal techniques based upon specification languages, the Booch method is a graphical technique for describing and thus specifying the behaviour of a system. In fact no one system is likely to be able to do everything, the best software engineers will use a mixture of these techniques.

Answer 3

Definitions of Software engineering on the Web:

The application of engineering principles and methods of design to the production of software.
www.usabilitysa.co.za/hcigloss.htm

The computer science discipline concerned with developing large applications. Software engineering covers not only the technical aspects of building software systems, but also management issues, such as directing programming teams, scheduling, and budgeting.
www.angelfire.com/anime3/internet/programming.htm

Applying scientific knowledge to the development, operation, and maintenance of software systems.
www.cs.wpi.edu/~gpollice/cs562-s03/ExamDefinitions.html

Software engineering is the profession concerned with creating and maintaining software applications by applying technologies and practices from computer science, project management, engineering, application domains, and other fields.
en.wikipedia.org/wiki/Software_engineering