I'm sometimes asked to explain the difference between proofreading and editing. Editing costs more. How's that? :-)

Rather than give sterile, dictionary definitions, I'll explain it using an example.

The following is the example text:

There are only3 ways to brish your teeth. Up & down, round & round, side 2 side. ALL ways use a soft toothbrush.

Below is the proofread version:

Here I have corrected spelling, fixed punctuation, written words in place of incorrectly-used numbers or symbols, and generally made the sentence kinder on the reader.

Below is the edited version:

Listed below are three recommended ways to brush your teeth:

• up and down
• around and around
• side to side.

It is also recommended you always use a soft toothbrush.

Proofreading has been done but editing is that plus more (hence the higher charge). The text has been formatted. It has been rewritten for clarity (rather than state these as facts, it needs to be made clear they are merely recommendations based on the author's point of view). The ideas have been grouped in bullet points: this adds structure and formality.

This is only a basic example. Proofreading is a basic tidying of text, correcting misspellings, and ensuring the text is legible and coherent, one sentence or paragraph at a time. Editing is all of the above but also looks at the big picture; the entire document. It ensures continuity of the document as a whole; that sentences make sense; that the idea is logical and structured as such. Editing often involves communication with the author to ensure meaning is not lost and that changes the editor wants to make are correct and do not change meaning. Editing often involves the use of a style sheet so that specific words are always written the same way: consistency is important.

Of course, the editor must also take into consideration the intended audience.