The sandbox is an isolated environment where you can create or edit data fields and design templates to standardize project work. You can also create public reports in the sandbox dashboard and test your changes using sandbox projects.
When you create the sandbox in the design center, Companion makes a copy of your live site. This can take a few minutes, depending on how many data fields, templates, dashboard reports, and projects you have.
After you create the sandbox, you can follow the high-level steps on the sandbox Home tab to create sitewide changes without affecting your live site.