AngularJS Tutorial - Understanding $apply and $digest (in depth)

-What is $apply -What is $digest -$apply vs $digest -When is Angular JS digest cycle invoked and when not -How to kick-in Angular JS digest cycle manually -How to work with events external to Angular JS (Context) -How to modify scope variables from jQuery (or external) events -How to update DOM when scope variables are modified outside Angular JS (Context) -How to update DOM when using jQuery events in Angular JS -Using $apply and $digest in Custom Directives -How do $apply and $differ in ng-repeat