The number one question I get asked is: What’s the difference between copyediting and proofreading? Copyediting takes care of the contents’ mechanics. Proofreading takes care of the final appearance.
I like to think of it as a play before opening night: during initial rehearsals actors memorize their lines and decide how their character would display emotions; during the dress rehearsal the director fine tunes certain movements, behaviours, or phrases to match his/her vision for the final show.
Proofreading is the last line of defence against mistakes and errors before production. Copyeditors are human (no, we don’t have any superpowers other than the innate ability to know where a comma is supposed to go) and do occasionally miss errors. The proofreader is a second set of eyes (often third or fourth or fifth) scouring through a final version. We look for things such as:

- Page layout issues
- single lines of a paragraph split up on different pages (widows and orphans)
- strange characters (such as my favourite enemy, the copyright symbol) inserted during font changes
- numbers accidentally replacing letters (10,o00) and vice versa (H3ADING)
- consecutive page numbers
- tables and images placed appropriately
- Document consistency
- all the headers and body text are their respective same font and size
- glossary/index and footnotes are used the same way throughout
- how tables and images are referenced
- and more!
