When I looked at the post-production comapany, Films @ 59, based in Bristol, I found it very confusing that there are online and offline editors working there. I have no idea what they do in two different roles, however, I have researched the definition on online and offline editing through several websites such as Wikipedia and mediacollege.com. Online and offline editing is very common in TV and other media projects which they hardly mentioned in film because of the blurred boundaries. I noticed that all of the offline editors working for Films @ 59, are freelancers.
Offline editing is actually a rough or draft cut of the project by editing a low-quality footage together, so the main editor and possibly director could get ideas for the final cut. Another role for an offline editor is to create an edit decision list (EDL) which is similar to log sheets (a list of shots). It is very important because once the offline editors done a list of the shots they put in a rough cut, the online editor would follow and make changes in order to edit a final cut. Offline editors can also make creative descisions; shots, cuts, dissolves, fades, etc.
Online editing is a final cut of the project by editing a high quality footage together. Online editors would reconstruct the final cut based on the EDL, created by the offline editors. They will add visual effects, lower third titles, and apply color correction. I noticed that the reason the offline editing has to be done first is because it is cheaper to use in a long period of time in contrast to online editing.