A photomontage is a collage constructed from photographs.
Historically, the technique has been used to make political statements and gained popularity in the early 20th century (World War 1-World War 2)
Artists such as Raoul Haussman , Hannah Hoch, John Heartfield employed cut-n-paste techniques as a form of propaganda…as did Soviet artists like Aleksander Rodchenko and El Lissitsky
Photomontage has its roots in Dadaism…which is closely related to Surrrealism
John Heartfield Hannah Hoch Raoul Hausmann
Raoul Hausmann Hannah Hoch