Proofreading is the act of reading through written material for errors – spelling, grammar, punctuation. All word processing programs have a spell checker, and I always recommend you start with that, but ONLY start with it, as these are far from infallible. If you’re the author of a piece and you know you aren’t great at grammar and punctuation, ask a friend for help (one, obviously, who IS good at it). It is important, however, to honor an author’s writing style in this process. If he or she capitalizes words for humorous or emphatic purposes, unless it’s a downright screaming error it should be left as is.
Now, I also do line editing, the task of looking at meaning rather than structure. Line editing is the act of reviewing the flow of the meaning. Are you using the correct word in context? (The old their – they’re – there dilemma.) Do the words and structure convey the meaning behind the words? Is a sentence out of place and better in context elsewhere? Did you repeat a phrase used earlier?
If you do or intend to write often, whether articles, blog posts or books, take the time to refresh your high school writing skills so you come across as the knowledgeable pro you are!