Groups let you add more than one person at a time. You can define user roles and visualize your statistics across all accounts. Perfect for teams and coaches who want to keep track of many accounts and understand exactly how individual actions affect the group performance.
On the other hand, if you choose to Connect to a Single Account, you give or receive access to only one account. There won't be a team dashboard at all. This is perfect for if you only want to collaborate with one single person at a time, or want to have a one-way-connection, meaning only you or the other person will have access to your inlytics data. It's also suitable for sharing access to the scheduling tool (we have deactivated sharing the scheduling tool for Groups to avoid abuse).