Agile software development is the mindset for developing software that derives from values agreed upon by The Agile Alliance, a group of 17 software practitioners in 2001. As documented in their Manifesto for Agile Software Development the practitioners value:Individuals and interactions over processes and tools Working software over comprehensive documentation Customer collaboration over contract negotiation Responding to change over following a plan

Software development is the process used to create software. Programming and maintaining the source code is the central step of this process, but it also includes conceiving the project, evaluating its feasibility, analyzing the business requirements, software design, testing, to release. Software engineering, in addition to development, also includes project management, employee management, and other overhead functions. Software development may be sequential, in which each step is complete before the next begins, but iterative development methods where multiple steps can be executed at once and earlier steps can be revisited have also been devised to improve flexibility, efficiency, and scheduling.