documentary · noun C /ˌdɑk.jəˈmen.t̬ə.ri/
documentary
B1 a film, television or radio program that gives facts and information about a subject
Dictionary examples:
The documentary took a fresh look at the life of Darwin.
They showed a documentary on animal communication.
Learner example:
It's supposed to be a documentary about a man who lives with his wife and dogs in The Rockies, in Canada. (Preliminary English Test; B1; French)