An Editor is a person who makes changes to documents.More specifically the word editor can mean:
a person who edits texts; see copy editing. A newspaper or magazine editor is a person who prepares articles for printing and sometimes chooses which articles to put in the newspaper. The main editor of a newspaper or magazine is called the "editor-in chief".
a Wikipedia user who makes changes (also called "edits") to pages ("articles")
text editor, an application program for editing an electronic text or media document