Documentaries have several purposes: to document facts and real events, to inform and educate audiences, and sometimes to investigate issues and attempt to create social change. There are different styles of documentary like observational, interviews, dramatization, and voiceover narration. The history of documentaries began with early photographers experimenting with capturing motion, and the genre evolved with lightweight cameras and synchronized sound. Documentaries can be fully narrated, follow a "fly on the wall" style with little narration, use a mix of styles, or include self-reflexive elements where the filmmaker appears. Common documentary types are docudramas which reconstruct events, and docusoaps which follow people's everyday lives.