An XML document is made up of one or more physical storage units called entities
Parsed internal general entity references like
Parsed external general entity references
Unparsed external general entity references
External parameter entity references
Internal parameter entity references
Reading an XML document is not the same thing as reading an XML file
The file contains entity references.
The file document contains the entities' replacement text.
When you use a parser to read a document you'll get the text including characters like <. You will not see the entity references.