BOM or Browser Object Model is a collection of methods and properties implemented by browser. It is frequently represented by a Window object, but it describes also other objects which used to be proprietary but are now considered practically a standard.

BOM objects
OBJECT DESCRIPTION
history Collects the list web pages that a user has navigated.
location Returns the information and navigation functionality of the currently loaded page.
navigator Gathers user's browser object information.
window Special function objects acting as arrays.

BOM methods
METHOD OBJECT DESCRIPTION
alert() window A system dialog pop-up messages used to alert users of potential incorrect actions.
assign() location Changes current URL to a new one.
back() history Shows the previous URL (if any in history list).
confirm() window A system dialog pop-up messages used to let users confirm or cancel prompted actions.
clearInterval() window Terminates execution of the timer set by setInterval().
clearTimeout() window Terminates execution of the timer set by setTimeout().
forward() history Shows the next URL (if any in history list).
go() history Shows a specific (given) URL (if any in history list).
open() window Opens a new window in the browser after being triggered by an event.
prompt() window A system dialog pop-up messages used to allow users enter data in same manner as they do with form fields.
reload() location Reloads the same document.
replace() location Replaces the current page with a new one.
setInterval() window Executes a function that is passed to it, in specified millisecond based intervals.
setTimeout() window Executes a function that is passed to it after set millisecond based time has elapsed.

BOM properties
PROPERTY OBJECT DESCRIPTION
appName (appCodeName) navigator Returns name of the browser.
appVersion (userAgent) navigator Returns version of the browser.
cookieEnabled navigator Checks if cookies are enabled.
hash location Returns or sets the hash (#) part of the anchor part of the URL.
host location Returns or sets the host name and port number of the URL.
hostname location Returns or sets the hostname of the URL.
href location Returns or sets the complete URL.
innerHeight (clientHeight) window Determines the document area's height of a window.
innerWidth (clientWidth) window Determines the document area's width of a window.
javaEnabled() navigator Checks if Java is enabled.
language navigator Checks browser's language.
length window, history Returns the number of items under history object or elements under window object.
origin location Returns the protocol, hostname and port number of the URL.
outerHeight window Determines the document area's height of a window, inclusing toolbars and scrollbars.
outerWidth window Determines the document area's width of a window, inclusing toolbars and scrollbars.
pathname location Returns or sets the path name of the URL.
platform navigator Returns OS where browser is installed.
plugins (with sub-properties) navigator Returns an array of plug-ins installed in the browser.
port location Returns or sets the port number of the URL.
product navigator Returns engine of the browser
protocol location Returns or sets the protocol of the URL.
search location Returns or sets a query string of the URL (or part of it).
screenX (screenLeft) window Determines X-axis position of a window with the respect to the viewport.
screenY (screenTop) window Determines Y-axis position of a window with the respect to the viewport.
userAgent (appVersion) navigator Returns version of the browser.