Much like Magento 1.0, Magento 2 is divided into modules. These modules are meant to encapsulate functionality related to a certain business feature. The framework provides organization for these modules, which can be found in the
app/code directory with the following convention:
(modulename) directory, there are a series of nested directories that contain the blocks, helpers, controllers, and models that make up a module. The hierarchy looks like this:
The following is a brief description of these directories and the programmatic ...