An electronic book (variously, e-book, ebook, digital book) is a book-length publication in digital form, consisting of text, images, or both, and produced on, published through, and readable on computers or other electronic devices.

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

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

A review is an evaluation of a publication, product, service, or company such as a movie (a movie review), video game, musical composition (music review of a composition or recording), book (book review), a piece of hardware like a car, home appliance, or computer; or an event or performance, such as a live music concert, play, musical theater show, or dance show. 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

SEO content is any content created with the goal of attracting search engine traffic. wikipedia.org

A blog (a truncation of the expression web log) is a discussion or informational site published on the World Wide Web and consisting of discrete entries ("posts") typically displayed in reverse chronological order (the most recent post appears first). wikipedia.org