Across a number of our projects in recent years, we have discerned a growing need for an online editor that can span the gulf between less structured or narrative documents and structured or templated forms. Note that these opposed terms are meant to be intelligible to the non-programmer, and interpreted in that light; "document" here does not refer to document-based non-relational storage or any other technical implementation.
A document refers to a linear body of formatted text, ie. the object one would author in any word-processing application (Word, Google Docs,...). Its contents are at least implicitly and historically organized around the metaphor of a paper document, with the structure of information built around formatting requirements of sections, paragaphs, headers, and so forth. A document is a singular and complete entity, in "one file" so to speak.