XML Schema vs. DTD

Main Difference

The term of XML is basically the short form of the EXtensible Markup Language. The main purpose of the XML Schema is to provide a standard way that must be simple in order to encode data and text in such an exclusive manner that the content will become capable of exchanging across the driver hardware, operating systems and applications for which very little human intervention should be required. The major functionality of the XML Schema is to demonstrate the structure of a XML document in the easiest form. The working of the XML schema is composed of imposing the constraints on the structure and the content of the chosen XML documents along with the syntactical rules that have to be followed in XML. The utilization of the XML schema is highly suggested by the World Wide Web Consortium (W3C).  This is the main cause that the use of the XML schema can be observed by and large. The DTD on the other hand, is the abbreviation of the Document Type Definition. The main objective of the DTD is to define the precise procedure of the elements of document needed to be ordered and nested. It is the DTD which will describe that what elements are integrated in the document and the characteristics of the built-in elements. The DTD describes the structure of documents in the markup languages of SGML-family.

XML Schema

xml-schemaThe obligation of the XML schema is to illustrate the structure of a XML document in the simplest shape. With the utilization of the XML schema, the elements that are able to appear in a XML document can be defined. Various sorts of attributes which these elements contain like an element is empty or it has given the authority of containing the text is defined by the XML Schema. The child elements are decided by the XML Schema together with the order of these elements. It is also the duty of the XML schema to describe the data types that are used in the elements and their attributes. The employment of the XML schemas is at the top these days in different types of web applications due to the reason that the XML schemas is extensible and fully supportive to the data types and name spaces in addition. Last but not the least, the XML schema is well equipped with the specific provisions that are needed for working with the data in databases and gives you full authority of making conversion between the data types at the same time.


dtdThe SGML-family markup languages such as SGML, XML, and HTML are used by the DTD in order to define the structure of documents. The main functionalities of the DTD are to define the accurate way of how the elements of documents are ordered and nested. The DTD is declared in a DOCTYPE declaration that is beneath the XML declaration in a document based on XML. In the body of the DTD, you will observe the definitions for the elements in the document in addition to their attributes.

Key Differences

  • You can guess from the XML Schemas that it must be written in the XML, while DTDs didn’t written is XML.
  • As compared to the DTD, the XML Schema is strongly typed.
  • You will not find the derived and built-in data types in the DTD as these are available in the XML Schema only.
  • It is the functionality of the DTD to allow inline definitions that is not available in the XML Schema.
  • The DTD is considered to be less powerful than XML schema.
  • With the help of the DTD, you can obtain the basic structure or grammar for the main aim of defining a XML document. You will discover the methods to define the constraints on the data contained in the document while using XML schema.

Video Explanation

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