Social groups are an important part of many cultures and societies. Caste is a term used to describe a social group based on birth or occupation, typically with a hierarchical structure. Sets are a group of people who share similar characteristics or interests. CLANS are a group of people related by blood or marriage. SECTS are a religious or philosophical group that has broken away from an established church or belief system. TRIBES are a group of people who share a common language, culture, and history. Sisterhoods are a group of women who are united by a shared purpose or goal.