In this blog post, we will explain how to easily create a "Hello, World!" module in Magento 2. Take note that the concept of local/community/core/folders only existed in Magento 1 and we don’t use them in Magento 2.
Steps To Create the Hello, World! Module
All of our custom modules in Magento 2 go under the app/code directory. The first step towards creating a module in Magento 2 is to create a folder inside your project directory named after the module. This will be where all the files related to the module will reside. The modules have a 2-part naming structure; i.e., Namespace/Module. This is so that the modules can be organized more efficiently.