Term	Description
Deprecated	Deprecated code is code that is no longer included in the language specifications. Generally this happens because it is replaced with more accessible or efficient alternatives.
DHTML	Stands for Dynamic HyperText Markup Language. DHTML fuses XHTML (or any other markup language), the DOM, JavaScript (or other scripts), and CSS (or other presentation definition languages) to create interactive web content.
Dither	In GIF and certain other image formats, there is a limited color palette used for each image. Because of this, not all colors in an image are presented. Dither is used to approximate these colors by combining pixels of different colors side by side.
DNS	Stands for Domain Name Service (alternately Domain Name System or Domain Name Server). Basically, it’s the thing that converts IP addresses into domain names. DNS servers are provided with the IP address of your web server when you assign your domain name to those servers. In turn, when someone types your domain name into their web browser, those DNS servers translate the domain name to the IP address and point the browser to the correct web server.
Doctype	The doctype declaration specifies which version of HTML is used in a document. It has a direct effect on whether your HTML will validate.
Dom, The	Stands for Document Object Model. It’s a language-indpendent, cross-platform convention for representing objects in XML, XHTML, and HTML documents. Rules for interacting with and programming the DOM are specified in the DOM API.
Domain	The domain is the name by which a website is identified. The domain is associated with an IP address. Domains can be purchased with any combination of letters, hyphens (-), and numbers (though it can’t start with a hyphen). Depending on the extension (.com, .net, .org, etc.), a domain can be anywhere up to 26 to 63 characters long.
DTD	Stands for Document Type Definition. DTD is one of several SGML and XML schema languages. It provides a list of the attributes, comments, elements, entities, and notes in a document along with their relationships to each other.