Plans: Whats the difference between a Collaborator and a Team Member?

Whats the difference between maxCollaborators(int) and maxTeamMembers(int) on Plans?

I.e:

    Spark::plan('SomePlan', 'someplan')
        ->price(10)
        ->maxCollaborators(5) /******* THIS *******/
        ->features([
            'First', 'Second', 'Third'
        ]);

VS.

    Spark::plan('SomePlan', 'someplan')
        ->price(10)
        ->maxTeamMembers(5) /******* THIS *******/
        ->features([
            'First', 'Second', 'Third'
        ]);