An article is a written work published in a print or electronic medium. It may be for the purpose of propagating the news, research results, academic analysis or debate. wikipedia.org

An essay is a piece of writing which is often written from an author's personal point of view. Essays can consist of a number of elements, including: literary criticism, political manifestos, learned arguments, observations of daily life, recollections, and reflections of the author. wikipedia.org

Writing is a medium of communication that represents language through the inscription of signs and symbols. wikipedia.org

Creative writing is considered to be any writing, fiction, poetry, or non-fiction, that goes outside the bounds of normal professional, journalistic, academic, and technical forms of literature. Works which fall into this category include novels, epics, short stories, and poems. wikipedia.org

Business English is English language especially related to international trade. It is a part of English for Specific Purposes and can be considered a specialism within English language learning and teaching; for example, the teachers' organisation IATEFL has a special interest group called BESIG wikipedia.org

Proofreading (also proof-reading) is the reading of a galley proof or computer monitor to detect and correct production-errors of text or art. Proofreaders are expected to be consistently accurate by default because they occupy the last stage of typographic production before publication. wikipedia.org

Professional writing involves the use of clear language to convey information in a way that is easily understood by the intended audience. Individuals who can use language well may be employed as full-time professional writers in a variety of communications-related occupations, such as wikipedia.org

Copywriting is the use of words and ideas to promote a person, business, opinion or idea. wikipedia.org

Article spinning is a search engine optimization technique by which blog or website owners post a unique version of relevant content on their sites. It works by rewriting existing articles, or parts of articles, and replacing elements to provide a slightly different perspective on the topic. wikipedia.org

A blog is a personal journal published on the World Wide Web consisting of discrete entries ("posts") typically displayed in reverse chronological order so the most recent post appears first. wikipedia.org

Search engine optimization (SEO) is the process of improving the visibility of a website or a web page in search engines via the "natural" or un-paid ("organic" or "algorithmic") search results. wikipedia.org