HTML(HyperText Mark-up Language) is a basic language used to describe visual elements in a web page. It was originally created as a markup language for formatting text. HTML is commonly used in the design of web pages and is the standard, used today, for manipulating text and visual elements. HTML used with Visual Basic Script can be used to access databases for ecommerce sites or utilitarian applications such as a job board, address book, or itemized stock. The HTML standard is slowly evolving to become the XHTML(eXtensible HTML) standard due to its versatility and compatibility with XML applications.

DHTML is a combination of Javascript and advanced HTML that takes advantage of HTMLs newer design capabillities such as colored scroll bars & cascading menus.
HTML is fine for your basic text and graphic site that needs light maintenance. However HTML alone is pretty boring. Usually HTML is used in conjunction with other scripting and programming languages such as: JavaScript for button rollovers and form validation, DHTML for layers, text effects and advanced drop-down menus, VisualBasicScript, for Database ASP and ecommerce applications, Server Side Includes for tracking, script inclusion and navigation, Cascading Style Sheets for ease of format and CGI for web applications and ecommerce.