In a Support Group, members provide each other with various types of help, usually nonprofessional and non-material for a particular shared, usually burdensome, characteristic.
The Support Group mentioned in The Fault in Our Stars was held weekly for cancer patients. The majority of the people attending this group were teenagers, as described by Hazel, the protagonist, 'The Support Group featured a rotating cast of characters in various states of tumor-driven unwellness'. The Support Group met every Wednesday in the basement of a stone walled Episcopal church shaped like a cross. The members of the support group sat in a circle right in the middle of the cross whether the two boards would have met, where the heart of Jesus would have been, this particular area of the church being referred to as the "Literal Heart of Jesus."
During the Support Group, about six or seven members attend and have the snack options of cookies and lemonade. Then they sat down in the Circle of Trust, and listened to Patrick, the Support Group head, talk about his experience with cancer.
The attendees then introduce themselves: Name, age, diagnosis, and how they were feeling that day. Once everyone had finished their introductions, Patrick, would ask everyone whether they had anything to share in the group.