CloudGround is source-available under the Elastic License 2.0. Its source is at github.com/cloudground-it/cloudground, which is also the module path of its Go code.

What each part is released under

Part	Licence
The panel, the agent, cgctl, the installer and the interface	Elastic License 2.0
The WordPress connector (connector/ in the source: the must-use plugin and the object-cache drop-in)	GPL-2.0-or-later

The connector has a licence of its own because it runs inside WordPress, as part of each site.

In plain words

Case	In practice
Allowed	Using, modifying and self-hosting CloudGround: on your own servers, for your own sites, and for the client sites you build and host, as long as the clients do not get access to the panel.
Not allowed	Offering CloudGround to others as a hosted or managed service: selling hosting where customers get the CloudGround panel or its features.
Anything else	Ask the maintainer before you rely on it.

This summary is not the licence: the binding text is the LICENSE file in the source, and connector/LICENSE for the connector.

Next step

To see what you would be running, read the architecture.