SDLC, V-Model, Water Fall and Agile Methodology

Software Development Life Cycle (SDLC) is a framework defining tasks performed at each step in the software development process.

V-Model has a little modification to SDLC model, where testing should be held in each phase of SDLC; not after coding.

1. Waterfall is a methodology that applies SDLC, where job on each phase should be completed before moving to the next phase. No way to back to the previous phase.

2. Agile is an alternative to Waterfall, and nowadays is popular in IT industry that allows to process projects part by part in short period of time, iterative and incremental way. It follows SDLC model for each iteration, and also shows you result soon.