MVC only templates
The layout file, on which the current MVC template is based on or a link to an existing page template, on which the current template is based. The system automatically generates the location path of the layout file based on Sitefinity CMS MVC templates conventions, for example,\ResourcePackages\Bootstrap4\Mvc\Views\layouts\default.cshtml. For more information, see Map new templates to a file in the file system.
Thus, you can easily check the resource package that the template uses, for example,Bootstrap4. You can also see how many and which pages use this template.
NOTE: If you modify the template name or delete the template altogether, you can still see the template in the list, along with the original automatically generated path.
Keep in mind that when creating a new MVC template from scratch, even when you do not base it on any existing template, the system still automatically generates the path where the layout file should be located, based on conventions. For more information, see For developers: Create MVC page templates based on layout files.
Web Forms and Hybrid templates
The master file, on which the template is based or a link to an existing page template, on which the current template is based.