In a group or club people come together with a common theme, topic, interest or denominator. Its focus is often on sharing, exchange, mutual support and networking, benefiting the group's members in the first place. Examples are an Internet based support group, a topic sharing group, e.g. coping with anxiety, a local co-counselling community or network, etc.
Your collaboration can also be focused on achieving deliverables benefiting people outside the group, such as maintaining a CCI business meetings archive or wring a manual.