Genre is any style or form of communication in any mode with socially agreed-upon conventions developed over time. In popular usage, it normally describes a category of literature, music, or other for
A genre painting, The Peasant Dance, c. 1568, by Pieter Brueghel the Elder
A film genre is a stylistic or thematic category for motion pictures based on similarities either in the narrative elements, aesthetic approach, or the emotional response to the film.
Western films are those "set in the American West that embod[y] the spirit, the struggle and the demise of the new frontier". Pictured: Clint Eastwood in the Spaghetti Western film A Fistful of Dollars (1964).