BOM and DOM - an overview
The JavaScript code in a page has access to a number of objects. These objects can be divided into the following types:
Core ECMAScript objects: This consists of all the objects mentioned in the previous chapters
DOM: This consists of objects that have to do with the currently loaded page, which is also called the document
BOM: This consists of objects that deal with everything outside the page-the browser window and the desktop screen
DOM stands for Document Object Model and BOM for Browser Object Model.
The DOM is a standard governed by the World Wide Web Consortium (W3C) and has different versions, called levels, such as DOM Level 1, DOM Level 2, and so on. Browsers in use today have different degrees of compliance with the standard, but in general, they almost all completely implement DOM Level 1. The DOM was standardized post factum after the browser vendors had each implemented their own ways to access the document. The legacy part from before the W3C took over...