SDLC - Software Development Life Cycle 

Sources and Online Definitions

Web-o-pedia

"SDLC is the process of developing information systems through investigation, analysis, design, implementation and maintenance. SDLC is also known as information systems development or application development. SDLC is a systems approach to problem solving and is made up of several phases, each comprised of multiple steps:

• The software concept - identifies and defines a need for the new system
• A requirements analysis - analyzes the information needs of the end users
• The architectural design - creates a blueprint for the design with the necessary specifications for the hardware, software, people and data resources
• Coding and debugging - creates and programs the final system
• System testing - evaluates the system's actual functionality in relation to expected or intended functionality."

Wikipedia

"Also called software development proccess, a structure imposed on the development of a software product. Synonyms include software life cycle and software process. There are several models for such processes, each describing approaches to a variety of tasks or activities that take place during the process."