The primary purpose of workspaces is to achieve flexible isolation of projects. Teams should be able to work independently without the possibility of stepping on each other but can work together if required. Consider the following real-world scenario:
Acme wants its engineering and marketing teams to work in isolation but for some marketing projects the marketing team should be able to bring in a few engineers on their project team. Acme also want a few people from the finance team access financials of projects from all departments. Plus, CXOs should have access to all projects in all departments.
Celoxis handles the above and many other real-world scenarios.
You can think of workspace as a department. In some cases, you can even map workspaces to geographical branches. It all dependens on how you want to segregate your projects and teams.
Only administrators can manage workspaces. To manage workspaces, go to Top Menu ▸ ▸ Admin ▸ Account Management ▸ Workspaces.