So let's assume now, if purely for the sake of argument, that you know what XML is. In fact, it is important to remember that the DOM itself is only an interface, and so implementations could differ slightly in their behaviors, requirements, and extensions. Yes, there is.
Higher levels add functionality on top of what lower levels provide.
This level merely represents the functionality already provided by Internet Explorer 3 and Netscape Navigator 3 and so represents a minimal functionality on which the DOM must build. The Level 1 specification was released as a recommendation on 1 October 1998, and can be seen here . Level 1 Level 1 was created with deliberately limited functionality. Someone, IMHO, was smoking crack. See the Level 1 abstract for more information.