Does JMS use the same Joomla Installation Print

YES, all websites share the same Joomla Installation.
In fact, a new 'multisites' directory is created and store all the 'configuration.php' parameters associeted to each website.
In such maner that we a domain is called, Joomla Multi Site select the appropriate 'conifiguration.php' file to connect the database and proceed with the request.