GitLab comes in two distributions: the Enterprise Edition and the Community Edition. If you're interested in using GitLab, we recommend you download and install GitLab Enterprise Edition.
The Enterprise Edition is available for free and includes all of the features available in the Community Edition, without the need to register or obtain a license. If you decide to upgrade to a paid tier and unlock additional features, you will be able to do this more easily if you are already on the Enterprise Edition.
GitLab is built on an open core model. GitLab Community Edition is open source, with an MIT Expat license. GitLab Enterprise Edition is built on top of Community Edition.
GitLab Enterprise Edition uses the same core, but adds additional features and functionality on top of that. These additional features are under a proprietary license that makes the code published source-available. For more information, you can find GitLab's license here.
Why use Enterprise Edition
If you have installed the Free tier of GitLab Enterprise Edition, you will get all the same features that are in the Community Edition distribution, but you have additional advantages:
If at any point in time you'd like to try paid features, you can do this without setting up a new instance or upgrading your existing instance. You simply enable the trial from within GitLab. If you're not satisfied with the paid features, your instance will automatically revert back to the Free tier features after the trial has expired.
To upgrade from Community Edition to Enterprise Edition you will have to make sure you're on the same version and follow specific steps, which often requires downtime. If you are using Enterprise Edition, upgrading to paid features is a matter of a single click.
Why use Community Edition
If you only want to download open source software, Community Edition is the best choice. This distribution does not contain proprietary code. Functionally, it will have the same features as the Free tier in the Enterprise Edition.
Note that in the future, if you decide to move to Enterprise Edition, an upgrade is required and may require downtime.