Explain how SDLC and STLC are interrelated with each other?

So far, all the questions and discussions revolve around differences between SDLC and STLC, but in order to understand differences between them its lot important that we understand how they are connected to one another. As we know SDLC has different phases, the phases from Requirement analysis to Coding phase deals with Verification part and post coding the testing phase starts where all the points verified till coding phase is validated.

So ideally, it’s the testing phase of SDLC, where the STLC begins. In terms of Venn diagram, we can say that STLC is contained within SDLC.

Based on above analysis, it can be said that STLC will come into picture only when SDLC exists.