There is some overlap between the two, but generally speaking, copy editing is when someone is trying to make a text more polished by looking for mistakes in:

• grammar
• spelling
• tone
• style
• wordiness
• uneven flow

By the time a person has finished copy editing a text, the text should be concise, on topic, and appropriate for the purpose while still reflecting the author’s meaning and voice. Copy editing can also involve making sure it meets particular guidelines set out by a publisher or school.

Proofreading usually comes after copy editing and is the final check before a text is published. A proofreader checks for mistakes in:

• grammar
• spelling
• punctuation
• formatting
• layout

Proofreaders aren’t so concerned with whether the ideas make sense or flow well together; they just want to make sure the text looks the way it should. This is one reason why copy editing takes longer than proofreading.