Rebecca Norlander , a seven-year veteran of Microsoft, started as a developer in the Office group, moved to the COM team as a program manager, and, early this year, joined the Internet Explorer Programmability team as a Lead Program Manager. Her overriding interest is in object-model technologies. A Node is the generic type that refers to all the objects that can exist inside a Document. The subset of nodes I talk about here is composed of Elements, Attributes, Text, and the Document itself. Elements are the things most often encountered while perusing a Document.
Elements encompass almost everything but text.
They derive from the Node type. TextNodes handle text in the Document. Attributes are essentially properties of Elements, therefore they are not child nodes of elements. Since they are not child nodes of elements, even though they derive from the generic Node type, they do not behave like other Nodes. For example, parentNode, previousSibling, and nextSibling will return NULL if called on an Attribute.