Design Web Format (DWF) represents 2D/3D drawing in compressed format for viewing, reviewing or printing design files. It contains graphics and text as part of design data and reduce the size of the file due to its compressed format. The reduced file size makes the distribution and communication of rich design data efficient. DWF doesn't require the recipient to know about the usage of CAD software that created the original drawing.
HTML (Hyper Text Markup Language) is the extension for web pages created for display in browsers. Known as language of the web, HTML has evolved with requirements of new information requirements to be displayed as part of web pages. The latest variant is known as HTML 5 that gives a lot of flexibility for working with the language. HTML pages are either received from server, where these are hosted, or can be loaded from local system as well.
You can also convert DWF into many other file formats. Please see the complete list below.