Panels-in-Panel vs Panels-in-Container

[v1p]

Hi, first of all, I am totally new to Sencha Touch framework , so apologies in advance if this is an acute n00b question.

I am trying to understand the functionality of various components of the framework, by reading the documentation, as well as referring to example app code. This confused me a lot , and literally made me bang my head, on desk.

When I generate a skeleton app using 'sencha generate app' command, the default view i.e Main.js extends 'Ext.tab.Panel'.
If I go check the Main.js of Twitter Example app, it extends 'Ext.Container'.

And there's another component called 'Ext.Panel'.

Now Panels within a Panel, support the tabBar thingy, whereas Panels within a Container doesn't.
I was quite excited to work on a multi-page(multi-view) mobile app, using MVC guidelines but got lost in the beginning itself .

Why there are multiple components, which can be used as global parent container, and what's the point, what should be used actually ?

[v1p]

Okie got the difference though. Going ahead with Container as the root element