JS BOM Introduction

Browser Object Model

The Browser Object Model (BOM) is used to interact with the browser. The default object of browser is window means you can call all the functions of window by specifying window or directly. For example: window.alert("hello javatpoint"); is same as: alert("hello javatpoint"); You can use a lot of properties (other objects) defined underneath the window object like document, history, screen, navigator, location, innerHeight, innerWidth.

The Window Object

The window object is supported by all browsers. It represents the browser's window.

All global JavaScript objects, functions, and variables automatically become members of the window object.

Global variables are properties of the window object.

Global functions are methods of the window object.

Even the document object (of the HTML DOM) is a property of the window object:

window.document.getElementById("header");

is the same as:

document.getElementById("header");