When developing an online store based on Magento 2, you might face the problem of extending the standard Magento 2 or Magento 2 extensions functionality.
Editing Magento core files or modules is not allowed because these changes will be overwritten during the upgrade.
So, how to make changes to the storefront (frontend) template file, css, js?
WARNING! The following instructions cannot be used to override the layout files.
Override module view-files in the app/code folder.
Let's say you need to change this file:
Make its copy in the theme folder with the following path:
Make the necessary changes to the newly created theme file.
If your own theme is missing from your Magento installation, create new theme.