Documentation may refer to the process of providing evidence (to document something) or to the communicable material used to provide such documentation (i.e. a document). Documentation understood as document is any communicable material (such as text, video, audio, etc., or combinations thereof) used to explain some attributes of an object, system or procedure. It is often used to mean engineering documentation or software documentation, which is usually paper books or computer readable files (such as HTML pages) that describe the structure and components, or on the other hand, operation, of a system/product.