Document

The most commonly accessed Document instance is.

getElementsByTagName
Finds every element in the document which has the specified tagName. The asterisk ("*") matches all elements.

getElementsByTagNameNS
Finds every element in the document which has the specified tagName and namespace. If the tagName is only the asterisk ("*"), all elements in the specified namespace will be returned.

getElementById
Finds the first element in the document which has the specified id. In Internet Explorer 7 or less, returns the first element with the specified name if the id is not found.