I've noticed references to different kinds of editors such as copy editor, line editor and development editor. I'd like to know the different categories of editors and their job descriptions.
A copy or content editor is the main editor for a project. They're the one looking at the big picture. Are there plot holes? Are the characters consistent throughout the piece? They also do editing for grammar, spelling, typos, etc. but they focus mainly on the story itself.
Line editors edit the piece line by line. They're looking primarily for grammar and spelling problems. They're generally paid less than copy editors since their job is usually easier.
A formatting editor does all the formatting for the book. They do the headers and page numbers, line spacing, and any special formatting that the publisher wants for their manuscripts.
A proofreader is usually the last person who goes over the book. They're looking for anything the others would've missed. They'll look and see if a page number got messed up some how, a typo that got missed, a sentence that got cut off, etc. They're generally unpaid interns or people who are paid with a free copy of the book.
The different kinds of editing come about through differences along two dimensions: first, the role of the edit in the journey from author's first draft to final typeset; second, the constitution of the editing as a process.
An answer of mine to a different question explains a difference in terms of role:
There are different kinds of editing. Proofreading is traditionally the last check of a text that has been prepared by typesetters, where it is assumed that the text is pretty much ready for publication. Then it is a matter of "fix spelling errors and very minor grammatical errors", but calling attention to the author of wider difficulties is entirely inappropriate. This is because time is usually very tight, because the publishers has a deadline, and large fixes cause costly work for the typesetter.
With editing before that stage, generally called copy-editing or developmental editing, bigger changes to the text are appropriate, and discussion with the author becomes useful.
The next big difference is in terms of what activity the edit unit is. The most important difference here is between line edits, which means the activity starts with the editor receiving the manuscript, who then works through the text and ends when the edited manuscript is handed back. The alternative is an edit which involves some kind of interaction and iteration. Proofreading almost always consists of a line edit, but earlier editing might follow one or other form. Cheapskate publishers might have a "copy-editing" process that consists of the project editor delegating a first line edit to someone, passing the edited version back to the author to correct, and then perform a second line edit themselves. Such a minimalist editing process would not be called developmental editing, which is more of a collaborative, exploratory process between editor and author. Developmental editing generally is a kind of high-grade copy-editing.
Note that there's lots of hedging words, like "traditionally" and "generally", excepting only the definition of line edit. That's because the variously named roles are not fixed, but evolve as the publishing workflow changes, as it inexorably does. For instance, the proofreading activity is quite different now, where electronic formats allow much more automation in the typesetting process, than was the case thirty years ago, when proofreading most often meant a demanding reconciliation of the final draft approved by the project editor to the original version submitted by the author, to eliminate the many errors that the editing process was sure to have introduced. So it is no surprise that there is difficulty finding crisp, widely agreed-upon definitions.