An opinion piece is a type of writing that expresses the author's opinion on a particular topic. It can take many forms, including a POST, an ESSAY, an EDITORIAL, a TRACT, and an op-ed. A POST is a short message or article published on a website or social media platform. An ESSAY is a written composition that expresses a point of view on a particular subject. An EDITORIAL is an article written by or on behalf of a newspaper or magazine that expresses the opinion of its editors or publishers. A TRACT is a pamphlet or short book expressing a strong opinion on a particular issue. An op-ed is an article written by a guest writer for a newspaper or magazine that expresses the writer's opinion on a particular issue.