Picture Editing in the industry

Film editing evolved from the process of a film editor physically cutting and taping together pieces of film, using a splicer and threading the film on a machine with a viewer such as a Moviola, or "flatbed" machine such as a Kem or Steenbeck.
 
The original editing machine:an upright Moviola.
 
Steenbeck film editing machine rollers
Before the widespread use of non-linear editing systems, the initial editing of all films was done with a positive copy of the film negative called a film workprint (cutting copy in UK). Today, most films are edited digitally (on systems such as Avid or Final Cut Pro) and bypass the film positive workprint altogether. In the past, the use of a film positive (not the original negative) allowed the editor to do as much experimenting as he or she wished, without the risk of damaging the original.
When the film workprint had been cut to a satisfactory state, it was then used to make an Edit Decision List (EDL). The negative cutter referred to this list while processing the negative, splitting the shots into rolls, which were then contact printed to produce the final film print or answer print. Today, production companies have the option of to bypass negative cutting altogether. With the advent of digital intermediate or "DI," the physical negative does not necessarily need to be physically cut and hot spliced together; rather the negative is optically scanned into computer(s) and a cut list is conformed by a DI editor.