Webopedia on Google+Webopedia on TwitterWebopedia on FacebookTech Bytes Blog
Main » TERM » D »

document type definition (DTD)

DTD is short for document type definition. The DTD states what tags and attributes are used to describe content in an SGML, XML or HTML document, where each tag is allowed, and which tags can appear within other tags.

Example of Document Type Definition

For example, in a DTD one could say that LIST tags can contain ITEM tags, but ITEM tags cannot contain LIST tags. In some editors, when authors are inputting information, they can place tags only where the DTD allows. This ensures that all the documentation is formatted the same way. Applications will use a document's DTD to properly read and display a document's contents. Changes in the format of the document can be easily made by modifying the DTD.

(Thanks to technical writer Ryan Mauldin for help in updating this definition.)







TECH RESOURCES FROM OUR PARTNERS
LATEST ARTICLES
SEO Dictionary

From keyword analysis to backlinks and Google search engine algorithm updates, our search engine optimization glossary lists 85 SEO terms you need... Read More »

Slideshow: History of Microsoft Operating Systems

Microsoft Windows is a family of operating systems for personal computers. In this article we look at the history of Microsoft operating... Read More »

Slideshow: Interesting Facts About Google Search

From Goats to Penguins, a server outage and trillions of searches, our slideshow presents interesting facts about Google and the Google.com... Read More »

STUDY GUIDES
Java Basics, Part 1

Java is a high-level programming language. This guide describes the basics of Java, providing an overview of syntax, variables, data types and... Read More »

Java Basics, Part 2

This second Study Guide describes the basics of Java, providing an overview of operators, modifiers and control Structures. Read More »

The 7 Layers of the OSI Model

The Open System Interconnection (OSI) model defines a networking framework to implement protocols in seven layers. Use this handy guide to compare... Read More »