A software development methodology is a framework that is used to structure, plan, and control the process of developing a project. It's applicable to web development too. There're many different types of methodologies that are designed for different types of projects and team.
However, not everyone can grasp the concept of each methodology, especially to those who aren't too technically-oriented. Here we have an interesting infographic called "Software Development Explained with Cars". By using car manufacture instead of software project plus visual representation, it should be easier to understand the difference of each popular methodology. This infographic is bought to you by toggl, a project tool for time tracking.