Groups WooCommerce grants memberships based on products. It automatically assigns a customer to one or more groups based on the products ordered.
Memberships can be sold through normal products where membership is granted for an unlimited time through one-time payments, or through subscriptions where the memberships lasts as long as the subscription is active, based on recurring payments and an optional setup fee.
If you want to charge a monthly subscription fee, the WooCommerce Subscriptions plugin is required, which adds a new subscription product type. Groups WooCommerce controls the memberships for the duration of the subscriptions.