In the beginning of film no editing was used and wasn’t actually necessary as seen in Arrival Of A Train by the Lumiere brothers in 1865 which had the audience fleeing the cinema believing they were about to be hit by a train.
In 1902 editing was first used as visual effects in A Trip To The Moon by George’s Melies where a quick cut is used to change the held items into stools. it also uses a fading cut to transition between scenes.
In 1903 Life Of An American Fireman by Edwin Porter was the first film to use a cross cut were two stories occur and it is left two the mind of the audience to link the two scenes together creating one overall story.
In 1915 D.W. Griffith made A Birth Of A Nation which used fast cuts to show violence and its result without showing impact so that the audience would put two and two together and picture the violence for themselves.
Then in Russia the shot film The Kuleshov Effect tested out using the same clip in multiple scenarios. the actor was congratulated on his subtlety even though he didn’t do anything
Eisenstein vertov then started to improve upon the use of montage with man with a movie camera.
jean luc godard then desided to change film from the old Hollywood therter style to new age film making breathless.
many people adapted montage such as Alfred Hitchcock in psycho as there are more cuts in the shower scene than seconds.
the conventions of editing were then used to create shock and supprise such as the scene from silence of the lambs were we expect the killer to get a knock on the door but it dosent happen.
today there is lots more editing as digital image makes it a lot simpler and it isnt just in films its also in gaming now but editing is used to build tension and make things seem faster and look better such as the Hogwarts battle scene from the deathly hollows part two
in this the shots are slow in the build up but fast in the action sequences. by using montage at various speeds the audience remains engaged and feels like they are taking part in the action. In this scene the action all seems to be occurring at the same time or chronologically when in real life each shot could have been filmed days or weeks apart.