GitLab Enterprise Edition includes advanced features and functionality not available in the Community Edition. An Enterprise Edition license is needed to enable these features. If you do not have a license, start a free trial. If a license is not uploaded, or expires, it will operate as Community Edition.
Upgrading is as easy as installing the Enterprise Edition package. You can downgrade if desired at any time, by re-installing the Community Edition package. There are no database schema differences between the two editions.