DHML used events, methods, properties to insulate dynamism
in HTML Pages.

Simple explanation :

If anyone use JavaScript in a HTML page, called DHTML.

DHTML: Dynamic HTML. An extension of HTML that enables, 
among other things, the inclusion of small animations and 
dynamic menus in Web pages. DHTML code makes use of style 
sheets and JavaScript.

DHTML: Dynamic HTML. An extension of HTML that enables,
among other things, the inclusion of small animations and
dynamic menus in Web pages. DHTML code makes use of style
sheets and JavaScript.

When you see an object, or word(s), on a webpage that
becomes highlighted, larger, a different color, or a streak
runs through it by moving your mouse cursor over it is the
result of adding a DHTML effect. This is done in the
language coding and when the file of the webpage was saved
it was saved as the .dhtml format instead of .htm or .html.

DHTML sites are dynamic in nature. DHTML uses client side
scripting to change variables in the presentation which
affects the look and function of an otherwise static page.
DHTML characteristics are the functions while a page is
viewed, rather than generating a unique page with each page
load (a dynamic website).

On the other hand, HTML is static. HTML sites relies solely
upon client-side technologies. This means the pages of the
site do not require any special processing from the server
side before they go to the browser. In other words, the
pages are always the same for all visitors - static. HTML
pages have no dynamic content, as in the examples above.

Pros and cons