Workspace is your environment in Scrumie where everything happens. It is a wrapper around your Teams and Projects.
Workspace is particularly important regarding User Permissions. You control who can create Teams, Projects, manage Billing or invite other people.
For more flexibility inside your organization Scrumie offers an unlimited number of Workspaces. This way - if you are a bigger organization - you can divide management across different business units which for example manage their own billing.