The subsites module provides a convenient way of running multiple websites from a single installation of SilverStripe, sharing users, content, and assets between them - the sites will be managed from a single CMS.
This module was provided by default in the CWP basic recipe in versions prior to 2.6.0. From this version onwards, you need to install it manually:
composer require silverstripe/subsites ^2.3
To learn how to set up a subsite in the CMS, visit the user documentation.
See DNS/Go-live for more information about setting up your DNS configuration for subsites.