What is a Document ?

A document is:

• a text
• that may be located
  • in the content of a file,
  • in the body of an HTTP request
  • in a database
  • in a string (memory)
  • … and more
• that has a particular structure (given by its mime for http or extension for a file, …)

Documents on the web (saved in a body request) have generally by nature a hierarchical nature (as opposed to tabular)

This is generally a HTML document but it can be also other type of document such as:

• an XML document
• an SGML instance.
• an SVG document
• a JSON document
• XUL
• Javascript
• text document (bag of words)
• …..

This document (file) can be rendered by the user agent (Generally a browser)

The term document in a file system is generally a file including its structure and format, e.g. fonts, colors, and images.

Database can store document in a field or as a row and offers function for document processing. See Database - Document Database

In natural language processing / full text search, a document is composed of word (term) known also as bag of word. See Natural Language - Document