javascript Range Description

The W3C DOM Range objectsimilar in concept to the IE TextRange objectrepresents a sequence of zero or more rendered text characters in a document. When a text range consists of zero characters, it represents an insertion point between two characters (or before the first or after the last character of the document). The Range object automatically keeps track of the node and character offset references for the start and end points of the range, so its methods can copy existing content, delete the range's contents, or insert new contents (in node form) into the existing range while maintaining the integrity of the document tree at every step. Nodeness is important to the Range object, but most of those concerns are handled for you.