How its "linked"? OpcPaymentMethod.schtml is used inside of OnePageCheckout.cshmtl

Hi Guys,
simple question for experienced dev. but i don't understand how do you "link" cshmtl pages together.
Example: OpcPaymentMethod.schtml is used inside of OnePageCheckout.cshmtl

Could you please, simply explain how its linked together? I can not find reference there...
Long time ago i used to work a lot with c#/aspx but MVC is completely new to me. It looks like it won't be so easy jump back to dev... Its not so obvious as defining reference for iframe ;-)

Please find attached screenshot, your reply is appreaciated.
http://www.matulo.sk/how-nopCommerce.jpg

Thanks, Peter

parnican wrote:

The part you showed is loaded by Ajax. :D

...hmmm, this will be lots of fun to learn MVC :)