THEMENAME.info.yml _files, provide Drupal with metadata about your theme, the features it supports, and the regions that it defines. All themes are required to have a THEMENAME.info.yml file, and creating one is generally the first step you'll take when creating a new theme.

In this article, we need understand:

• Create a new .info.yml file and define a new theme
• Review the required key/value pairs of an .info.yml file
• Enable our new theme in the Drupal UI