A document is a written, drawn, presented, or memorialized representation of thought. The word originates from the Latin documentum, which denotes a "teaching" or "lesson": the verb doceō denotes "to teach". In the past, the word was usually used to denote a written proof useful as evidence of a truth or fact. In the computer age, "document" usually denotes a primarily textual computer file, including its structure and format, e.g. fonts, colors, and images. Contemporarily, "document" is not defined by its transmission medium, e.g., paper, given the existence of electronic documents. "Documentation" is distinct because it has more denotations than "document". Documents are also distinguished from "realia", which are three-dimensional objects that would otherwise satisfy the definition of "document" because they memorialize or represent thought; documents are considered more as 2 dimensional representations. While documents are able to have large varieties of customization, all documents are able to be shared freely, and have the right to do so, creativity can be represented by documents, also. History, events, examples, opinion, etc. all can be expressed in documents.