A workspace is the top-level resource which is used to group projects. A workspace can only be created by a root user, which you only have access to if you own a particular instance. You can have multiple workspaces per instance. Every workspace will have a unique key, per instance.
Your organisation can scope all projects under a single parent workspace. If you are a large organisation managing your own instance, you may wish to have one workspace per department/team. This allows you to organise projects on a per-team basis. However, we recommend you to use a single workspace to scope all your projects and add tags to projects to organise them on a per-team level.