Documentation is any communicable material that is used to describe, explain or instruct regarding some attributes of an object, system or procedure, such as its parts, assembly, installation, maintenance and use. Documentation can be provided on paper, online, or on digital or analog media, such as audio tape or CDs. Examples are user guides, white papers, online help, and quick-reference guides. Paper or hard-copy documentation has become less common. Documentation is often distributed via websites, software products, and other online applications.