In Simple

The System View is Server View, Repository View is Local View/Copy ( Content ) , Project View is not need for newer version.

The Repositories View

You can browse and perform actions on the contents of the SAP HANA Repository on a specific SAP HANAsystem.

The Repositories view displays the contents of the repository on a specific SAP HANA system.You can navigate the package hierarchy and check out project files from the SAP HANA Repository; the checked out files are downloaded to the workspace on your local file system, where you can work on them and modify them as required.

The Repositories view is a list of repository workspaces that you have created for development purposed on various SAP HANA systems. Generally, you create a workspace, check out files from the repository, and then do most of your development work in the Project Explorer.

However, with more recent versions of SAP HANA, you can use the Repositories view to perform actions directly on repository objects in multiple workspaces, for example: edit objects, activate objects, and manage object versions - all without the need to set up a project. TheRepositories view also provides direct access to lifecycle-management tools.

The Repositories View - SAP HANA Developer Guide for SAP HANA Studio - SAP Library