A literary genre is a category of literary composition. Genres may be determined by literary technique, tone, content, or even (as in the case of fiction) length. The distinctions between genres and categories are flexible and loosely defined, often with subgroups.
Essay – a short literary composition that reflects the author's outlook or point.
Owner's manual (also Instruction manual, User's guide) – an instructional book or booklet that is supplied with consumer products such as vehicles, home appliances, firearms, toys and computer peripherals