What is the difference between a film opening and a film trailer?

Opening
-Enigma codes (hook)
-Charecter roles limeted to 'hero' (Propp) Protagonist
-Establishing shot for setting, action sots or codes (Barthes)
-Charecter in role/doing same thing
-Hint towards disequilibrium but not nesessary as it is 2 mins
-Title/be imaginative and fit genre
-Do we want to watch on?
-Music/does this fit the genre?

Trailer
-Provides a summary of the film, plot iotuline (without the ending)
-Enigma codes
-Charecter roles (Propp) more clearly defined
-Varied clips from entire film