Line editing
Suggest improvements to overall structure
Rearrange paragraphs or larger manuscript sections
Improve clarity and flow
Eliminate redundancy, tighten language
Ensure consistent tone appropriate for intended audience
Copyediting
Correct spelling, grammar, punctuation, and usage
Ensure the manuscript conforms to the relevant style guide (Chicago Manual of Style, AP, or a style guide specific to a particular journal or company)
Ensure consistency and appropriate formatting of citations
Check cross references
Identify inaccurate word choices
Indexing
Proofreading
For manuscript proofs (PDFs, EPUB and MOBI files, printed galleys):
Correct typos, spelling, grammar, and punctuation
Check running heads
Check page numbering
Check for widows, orphans, ladders, and bad line breaks
Check that headers are the appropriate level
Check for loose or tight lines