There are three hierarchical levels in Upwave:
A workspace is typically one organisation. Inside your workspace you can create as many teams (and boards) as you like.
A team can be any type of subset of members and work. For example an organizational department (HR, management, production etc.) or a project.
How you structure your workspace and team(s) will depend on the size of your organization, and the nature of your work. Sometimes a team is permanent (such as a HR department), and at other times it is temporary, such as a project.
In Upwave you can safely invite external collaborators, for example to a project. They only get access to what you invite them to, or information that you have set as public. Read more about team permissions.