Symfony 3:[Code Structure]

myproject/
    config/
    src/
        Controller/
        Entity/
        Form/
        Migrations/
        Model/
        Repository/
        Service/
        [components]
    templates/

Description:
Entity/: Refers to the Persistence Layer

Example:
Let’s assume we have an entity Product, consisting of id and name.

1) Start by creating Product directory
A bundle is simply a structured set of files within a directory that implement a single feature. Each directory contains everything related to that feature, including PHP files, templates, stylesheets, JavaScripts, tests and anything else. Every aspect of a feature exists in a bundle and every feature lives in a bundle.