There are six main phases in the software development life cycle (SDLC): 1. Requirement gathering and analysis to determine user needs and specifications. 2. Design to develop the system architecture and design based on requirements. 3. Implementation/coding to divide work into modules and write code. 4. Testing to ensure the software meets requirements through unit, integration, and other testing. 5. Deployment to deliver the product to customers for beta testing and final release. 6. Maintenance to provide ongoing support and solve problems after customers begin use. Each phase produces deliverables and handoffs to guide the next phase.