Explain the difference between SDLC and STLC

SDLC (Software Development Life Cycle):

• Complete process of software development from planning to deployment
• Includes all phases: Requirements, Design, Development, Testing, Deployment, Maintenance
• Focuses on building the entire software product
• Involves all stakeholders: developers, testers, business analysts, etc.

STLC (Software Testing Life Cycle):

• Subset of SDLC focused specifically on testing activities
• Phases: Requirement Analysis, Test Planning, Test Case Development, Environment Setup, Test Execution, Test Closure
• Focuses on ensuring quality through systematic testing
• Primarily involves QA team and test managers

Key Relationship

STLC is a part of SDLC. While SDLC covers the entire software development process, STLC specifically deals with the testing phase and its sub-activities. STLC runs in parallel with SDLC phases to ensure quality at every stage.

STLC Phases

1. Requirement Analysis: Understand testable requirements
2. Test Planning: Define test strategy and resources
3. Test Case Development: Create detailed test cases
4. Environment Setup: Prepare test environment
5. Test Execution: Run tests and log defects
6. Test Closure: Analyze results and document learnings