Understanding unique vs multiple membership(s) (using Webform)
The Webform integration determines whether to add or update a membership based on the "Membership Organization" of the membership type. Say you have the following membership types defined:


Organization: Soccer Club

Membership Types:


Youth soccer
Teen soccer
Adult soccer

Organization: Tennis Club

Membership Types:


Youth tennis
Teen tennis
Adult tennis



Now say you have signed up a person for a "Youth soccer" membership. If you subsequently sign them up for a "Teen soccer" membership, Webform will detect that you are upgrading membership within the same organization and it will bump their existing membership from youth to teen. If however you sign them up for a "Teen tennis", it will leave their soccer membership alone, and add the tennis additionally.