With advent of Desktop publishing, the process of editing became revolutionized. The possibility of editing compositions on-screen has made the task of professionals both easy and cheap.
It is asserted by media gurus that post-digitization, wordsmiths and grammarians are required but those who know Quark have the edge in crisis.
Moreover, a regular copy editor today is expected to be simultaneously producing an SEO(Search Engine Optimization), a copy not just suitable for web but targeted most frequently in search terms and making the text visible during browsing quests of prospective readers.
Based on current trends, editing has evolved into the following types:
Developmental Editing
When qualitative editing is required at the manuscript level for a Work in Progress(WIP) or when the manuscript is complete. It deals with story-telling techniques and writing skills and sometimes with the book design including placement of chapters.
It may require re-writing the story or re-working the plot.
Substantive Editing/Content Editing
Even a promising manuscript requires editing. The narrative may be engaging, the writing skills may be enviable and yet editing may be required for consistency and coherence. It may be desirable in keeping with norms and conventions of storytelling and even where there are deviations to create a cogent impression.
Some characters may need to appear more flesh and blood, certain loose-ends may require tying up, some images may be unintentionally left incomplete and may need finishing touches.
The intention of the author shall be executed by the editor in substantive editing.
Stylistic Editing/Line editing
This editing is executed for paragraphs and sentences.The aesthetic impression is consolidated by balancing narrative with dialogue or focalization with performative elements.Simply, what is told and what is shown and how...
Copy editing
Not to confuse with stylistic editing or line editing, it is copy editing that turns out a manuscript that conforms to the style sheets as per the convention.
It aims at refining the syntax and removing inconsistencies that may be factual, chronological or grammatical.
Proofreading
It double-checks the manuscript and eliminates any errors and inconsistencies especially in spellings, punctuation and grammars left over by the copy editor.
For clear and better information on the subject:
http://www.romancerefined.com/types-of-editing.html