The primary purpose of a software development lifecycle (SDLC) is to provide a structured framework for developing software applications from initial concept to deployment and maintenance. This process typically includes stages such as planning, design, coding, testing, and release. By following an SDLC, development teams can ensure that their projects are organized, efficient, and meet user requirements. It also helps identify potential risks early, allows for better communication among stakeholders, and improves overall software quality through systematic evaluation.