N00b Questions about track2

Hi,

First, sorry for waisting your time with my noob question but i need some explanation about structure of track2:

Example:
1111222233334444=02021010123456700000

So to be sure:

1111222233334444= cc number?
0202= expiration date ?
101= type of card (101/201...)?

But my the question is for the last:

0123456700000= special bank code ?

About this code, does this code is the same for all card from this bank ?
Ex: all visa from barclays in uk have the same number?
Or does it change from location?
Ex: Code from London barclays visa is different than Newcastle barclays visa
Or is it a unique id different on all the cards ?

By advance thanks for your time, i know i m a useless n00b, show me the light ^^

Thanks for reply juno20.

Seems to be a difficult subject, i have read about pvn (if someone can explain ?) and the old trick with cvv like =020210100000CVV

But depent of the dump ... lot of different format of track2...

I don't try to generate track2 to use fullz but just want to understand the meaning of this numbers.

Thanks bro for your help, very appreciated!
Will read this carefully