Workspaces comprise apps, which pertain to the same application area, and are located in the left menu. They are intended for specific activities of a company, such as personnel management, finance, records management, and so on.
A Finance section can include such apps as "Invoice" and "Cash Request". A Document Management section can consist of these apps: "Contract", "Memo", "Administrative Note", and "Acceptance Certificate".
With the Configure Workspaces option, you can change the order of Workspaces in the left menu.
To learn more about workspaces, read these articles: