What is editing?

The best way, I find, of trying to define something is to write your own definition.

This, based on the films I've edited, is mine.

Editing is the creative process of finding a story and making it as interesting as possible.

There are much better definitions out there, I'm sure.

Others like: "On its most fundamental level, film editing is the art, technique, and practice of assembling shots into a coherent whole."

But I find that a bit wordy and slightly cold.  

You know you have to put shots together, that's a given, what you maybe didn't know is that you have to FIND a story.  And that story may not be the one written on the script.  

As you know, a script doesn't say anywhere near as much as a picture, which contains thousands of extra pieces of information you can't write down (facial movements, the intonation of the actor's voice, the colour of the sky, what is in the background, who is looking at whom)

The second part, making it as interesting as possible, is how you tell that story.  How you present the story, how you engage the audience.

The question of what editing is, can't really be divorced from what is good editing.  One is the other.

Which leads nicely into Walter Murch. 

Who, as a world famous editor, has also written some great stuff on what makes great editing.

But first, here's an intro video of what editing is about.

As one editor says, "editing is what you are always looking at"