A staging environment (stage) is a nearly exact replica of a production environment for software testing. Staging environments are made to test codes, builds, and updates to ensure quality under a production-like environment before application deployment.
A development environment is where a developer tests code and checks whether the application runs successfully with that code. Once the application has been tested and the developer feels that the code is working fine, the application then moves to the staging server.
To create a staging or development environment you can 'Copy From' either production, development or staging, 'Install Repository' from Git or start with a clean slate by selecting 'Install Fresh WP'.
Once created, you can 'Move' and 'Copy' your files and/ or database from and to each of your environments.