William Blake, first draft of “The Tyger” (Wikipedia)
[transcription of draft]
William Blake, “The Tyger” from Songs of Innocence and of Experience, 1795, relief and white-line etching with hand colouring
Although many writers and even some instructors use the terms editing and revising interchangeably, it is helpful to see editing and revising as two different activities. For the purposes of this discussion, editing involves going through a piece of writing and making comments and suggestions about how it could be better—or whether it is appropriate at all, even if it is your own writing. Revising, on the other hand, occurs when you attempt to make the changes suggested during the editing process. For example, an editor might suggest that you tweak your introduction to make it better fit the rest of the paper. The actual process of changing the introduction is revision, and it comes with its own set of difficulties.
You can (and should) edit your own work. This simply means going back over what you have written and finding ways to improve it. Most writers frequently switch between drafting new sentences and paragraphs and editing ones they have already written.