Magento 2 - Build World-Class online stores

Developing the module

To start the module development, we will declare the basic module configurations. Open your favorite code editor, create a new file called module.xml, and save the file in app/code/Packt/TweetsAbout/etc. Enter this code in the file:

<?xml version="1.0"?>
  <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
      <module name="Packt_TweetsAbout" setup_version="2.0.0"/>
  </config>

Magento 2.0 works with Uniform Resource Names (URN) schema validation to reference XML declarations, as you can observe in the <config> tag. The module.xsd file works by validating whether your module declaration follows the module declaration schema.

The <module> tag contains ...