Chrome debugger

Source

Allow to list all js script.
First use source tab to see only js script loaded from your domain and other domains.

Options at the bottom
beautyfier : indent javascript code to increase readability
pause on exception : if there is an error pause.
Console : write a javascript code in console

Right panel, the step by step debugger toogle a right arrow to activate all break point or descativate all break points

Network

Network are logged only if a page is loaded when the network tab is active.
It load all http request included ajax call and ajax retrieved js

The "sens interdit" button allow to clear all logged file for example, when after an ajax call, news request has been made.