The list of connected domains retrieved by this tool is based on the public facing IP address that is associated with the request.
The output shows other domains that are known to use the same IP.
This allows you to either spy on competitors or check the information that can be found about your own domain.
These other domains may be subdomains, or other resources used by the same company.
If the domain analyzed is found behind a CDN or other proxies, the list of connected domains may include resources that the CDN provider has associated with the public IP.