The term CDATA, meaning character data, is used for distinct, but related, purposes in the markup languages SGML and XML. The term indicates that a certain portion of the document is general character data, rather than non-character data or character data with a more specific, limited structure.
In an XML document or external parsed entity, a CDATA section is a section of element content that is marked for the parser to interpret as only character data, not markup. A CDATA section is merely an alternative syntax for expressing character data; there is no semantic difference between character data that manifests as a CDATA section and character data that manifests as in the usual syntax in which “<" and "&" would be represented by "<" and "&", respectively.
A CDATA section starts with the following sequence:
and ends with the first occurrence of the sequence:
All characters enclosed between these two sequences are interpreted as characters, not markup or entity references. For…