These data sources are available from Marketing Cloud as a starter bundle. They provide basic contact data, such as email address, mobile number, and device ID, as well as engagement data, such as email opens,clicks, bounces, unsubscribes, SMS sends, deliveries, opt-outs, and push sends, opens, and opt-outs. References:
https://help.salesforce.com/s/articleView?id=sf.c360_a_data_cloud_marketing_cloud_data_foundation.
htm&type=5