The ALM Octane model consists of:
On-premises: A site, which contains spaces.
Spaces, which represent, for example, a business unit. Spaces contain workspaces and customization entities.
Workspaces, which represent, for example, an application and its entities within the business unit—such as user stories, tests, defects, and so on.
The model operates on these contexts, which are also the entry points into the REST API. Every entity exists in one of these contexts. For details, see Entry points and contexts.