More examples on KA04

Hello all.

I’m trying to work with the ethernet shield KA04. I found the example ka04_sample, it even works, great. Now I want to actually write a program. Where can I find some tutorial or examples explaining the principle of work of this EtherCard.h library?
For example, I want to understand what the functions ether.packetReceive(), ether.packetLoop are, when and how I can write to the server with the bfill.emit_p, how can I read what is written on the server or what the parameters of the request sent by a browser.

I wrote programs for Arduino Ethernet Shield 2. Somehow, there is no any Arduino Ethernet Shield 2 in the store, only Velleman’s.

Thank you.