There are 7 types of documentaries: docusoaps, reality TV, fly on the wall, mixed, self reflexive, docudrama, and fully narrated. Docusoaps follow individuals or groups over time in an observational style. Reality TV progressed in the late 20th century and mixes authentic material with entertainment. Fly on the wall documentaries film events without subjects' awareness. Mixed documentaries combine interviews, footage, and narration to advance the narrative.