How Does a Copyeditor Differ From an Editor?

Note: These are rough definitions.

A copyeditor (which I’m using as a synonym of proofreader) focuses mainly on the following:

 typos
 grammar
 punctuation
 consistency

What does “consistency” mean? Let’s say the writer prefers the Oxford comma. It’s then the editor’s job to make sure this comma is always used. Ditto for how many spaces to use between sentences (please, only one); spelling out numbers; which dash to use (en or em, never a hyphen); and the like.

By contrast, an editor focuses on everything. This includes:

 formatting
 factual mistakes
 cogency
 clarity
 tone
 flow

Again, these are general guidelines that I present to clients. Other editors likely use their own distinctions.