feature film vs silver screen

feature film

noun
  • The main, full-length film in a cinema program that also included a short film and often a newsreel. As of now, it plays after the trailers. 

  • Any film produced to be shown in cinemas before being released for home viewing. 

silver screen

noun
  • A cinema screen onto which movies are projected. 

  • By extension, movies, or that which is related to movies or cinema. 

How often have the words feature film and silver screen occurred in a corpus of books? (source: Google Ngram Viewer )