Why are some Text nodes empty

Why are some Text nodes empty?

Answer:

In XML, all whitespace has to be passed through to the application. This means that if you have whitespace, such as carriage returns, between tags in your source file, these have to be passed through, even if they're just there for pretty-printing. The DOM implementation has to put this whitespace somewhere, and the only possibility is a text node. Thus you will get text nodes which look empty, but in fact have a carriage return or other whitespace in them.

Note that some DOM implementations, which do not consider whitespace in element content to be meaningful for the XML languages they support, discard these whitespace nodes before exposing the DOM to their users.

See also the parameter "element-content-whitespace" in the DOMConfiguration interface provided by DOM Level 3.