JavaScript BOM (Browser Object Model) Introduction
Example
The BOM (Browser Object Model) contains objects that represent the current browser window and components; objects that model things like history, device's screen, etc
The topmost object in BOM is the window object, which represents the current browser window or tab. 
- Document: represents current web page.
- History: represents pages in browser history.
- Location: represents URL of current page.
- Navigator: represents information about browser.
- Screen: represents device's display information.
