Use of some kind of editor program to modify a
document. Also used to refer to the modification itself,
e.g. "my last edit only made things worse".
To edit something usually implies that the changes will
persist for some time, usually by saving the edited document
to a file, though one might open an editor, create a new
document in memory, print it and exit without saving it to
Editing is normally done by a human but see, e.g., sed.