What does "packages" property of requireJs config mean ? And how it works? - angularjs

Question

I am trying to understand how requireJs works. There is a property "packages" which I came across while configuring requireJs. What my understanding is that 'packages' is used to mention a complete folder/module which contains "main.js" & main.js requires all other dependencies inside that module. But does mentioning "packages" in config file will automatically load main.js or do we need to do something to make it load main.js ?
Below is my folder structure & main.js snippet. 'main.js' is the data-main or entry point of application.

Answer 1

So after trying few stuff, what I understood is that packages lets you mention a directory or folder which has other modules (commonJs directory is what docs refer it to). So the way we define a package is :
packages: [
{name : 'controllers' , location :'../controllers' },
{name : 'directives' , location : '../directives'},
{name : 'services' , location : '../services'}
] ,
Where name is an alias for this entire directory or folder. location is the path of the folder relative to your main.js or requireJs's config file.
Now answering the 2) point - it does not load automatically. For it to load we need to require it somewhere. Once we require it, requireJs will first load the main.js inside that directory by default. And we need to define all the other modules inside that directory, in this main.js. For eg- I will require it in my app.js before bootstrapping my application-
require([
// Add additional dependencies
'angular',
'angular-ui-router',
'jquery',
'app',
'route',
"controllers",
"directives",
"services"] , function(){ console.log("All dependencies loaded"); });