Broadly speaking its a model for doing something if you find yourself developing websites that always do the same things like manage user access, display data, facilitate upload of photos, manage access to a back end database eventually you are going to start designing these websites in a similar way to make it quicker to do and easier to change going forward. What you are creating is a framework. I think at a more detailed level a php framework might be a way to create and manage objects, classes, database interaction. Thats just some thoughts from a fellow beginner.