A membership is a product players buy from you. A cohort is a group you use to give players benefits. A membership on its own gives no benefits until you link it to a cohort.
How they work together
Create the memberships you want to sell, for example Junior and Adult.
Create a cohort, for example "Members".
Link both memberships to the cohort.
Use the cohort in your price lists and rules.
Everyone with an active Junior or Adult membership now gets the "Members" benefits.
Good to know
One membership can be linked to several cohorts.
A cohort can also contain players without a membership, such as coaches or staff.
Players see memberships in the app. They never see cohorts.