3. Difference between SDLC and STLC?

Generally, Interviewer kicks off interviews with this question.

When I was asked the same question, I responded with a very standard answer; “SDLC - a systematic approach to develop a software and STLC - process of testing software in a systematic and planned way.” 

Interviewer: “How can you relate six phases Requirement, Design, Development, Testing, Deployment & Maintenance to Software Testing Life Cycle?”

Let’s see how I related these six phases with STLC:

S.No.	Phase	SDLC - Software Development Life cycle	STLC - Software Testing Life Cycle
1.	Requirements Gathering	Requirements gathering is done by business analyst. Development team analyse the requirements from the design, architecture & coding perspective.	Testing team also review & analyse the requirements. Testing team identifies the testing requirements like what types of testing will be required and review the requirements for logical functional relationship between various features / modules, so that any gaps can be caught at an early stage.
2.	Design	Technical architect works for the high level & low design of the software. Business analyst works for the UI design of the application	Here, test architect generally the test lead/manager, does the test planning, identify high level testing points. Basically, requirement detailing is done in this phase.
3.	Coding or development	Development team does the actual coding based on the designed architecture.	Testing team write the detailed test cases.
4.	Testing	In SDLC, actual testing is carried out in this phase. It includes unit testing, integration testing & system testing etc..	Test Execution and bug reporting, manual testing, automation testing is done, defects found are reported. Re-testing and regression testing is also done in this phase. But, I don't agree with this statement. So, if I want to relate the testing phase with STLC, I would say it it is testing of test cases & test plans i.e. is basically review of test cases, test scenarios etc..
5.	Deployment	Application is deployed on production environment for real end users.	Final testing and implementation is done is this phase and final test report is prepared. For this statement as well, I don't agree. For software / application deployment is basically, when it is installed for real use. So, this way, STLC, deployment would be when test when test cases getting used i.e. execution of test cases.
6.	Maintenance	Basically, it includes, post production / deployment support & enhancements.	Most of people say - Maintenance testing is carried out in this phase. My definition for this is - updation & maintenance of test plans, test case required for the testing of support requests & enhancements as a part of maintenance.