OPposite the EDitorial page (newspaper opinions/viewpoints) Op- Ed

a newspaper page opposite the editorial page, devoted to personal comment, feature articles, etc.

The op-ed is usually longer than a regular letter to the editor. It is often written by a subject matter expert and is an example of an instance when a freelancer produces copy as a ghostwriter under someone else's byline. ... An op-ed can also be written by an employee, such as a staff writer.