Question - What does an XML document actually look like (inside)?
Answer -
The basic structure of XML is similar to other applications of SGML, including HTML. The basic components can be seen in the following examples. An XML document starts with a Prolog:
1. The XML Declaration
which specifies that this is an XML document;
2. Optionally a Document Type Declaration
which identifies the type of document and says where the Document Type Description (DTD) is stored;
The Prolog is followed by the document instance:
1. A root element, which is the outermost (top level) element (start-tag plus end-tag) which encloses everything else: in the examples below the root elements are conversation and titlepage;
2. A structured mix of descriptive or prescriptive elements enclosing the character data content (text), and optionally any attributes (‘name=value’ pairs) inside some start-tags.
XML documents can be very simple, with straightforward nested markup of your own design:
Hello, world!
Stop the planet, I want to get
off!
Or they can be more complicated, with a Schema or question C.11, Document Type Description (DTD) or internal subset (local DTD changes in [square brackets]), and an arbitrarily complex nested structure:
]>
Hello, world!