What is the role of aura:waiting and aura:doneWaiting in Lightning Component in Salesforce ?

Hi Kirandeep,

aura:waiting : This event is automatically fired when a server side apex action is added using $A.

aura:doneWaiting : This event indicate that the lightning component is done waiting for server response.

This event is always fired after aura:waiting.

It is handled by a client-side (java Script) controller.