The Software Development Life Cycle (SDLC) refers to a methodology with clearly defined processes for creating high-quality software. in detail, the SDLC methodology focuses on the following phases of software development: Requirement analysis Planning Software design such as architectural design Software development Testing Deployment The three major phases of testing include: unit testing, integration testing, and user testing. Discuss why testing is a major step in the SDLC and why each phase must be completed before deployment.