DTD

A Document Type Definition (DTD) is a set of rules that defines the structure, elements, and attributes of an XML document. It specifies what types of data can appear, how they are organized, and their relationships, ensuring consistency and correctness across documents. Think of it as a blueprint or blueprint that guides how information should be formatted and arranged within an XML file, helping computers and users understand and validate the data’s structure. This makes data exchange more reliable and standardized across different systems and applications.