Well... I really hope that I am not the biggest nerd around here.
Atm I've searched the whole freaking internet, including wikipedia, and I really can't figure this stack out.

I know it is a four-layered model, which you can compare to the 7-layered OSI-model, but only with an "Application layer", "Transport layer", "Network/Internet layer" and a "Link layer".

But what is the connection between those layers?
Application layer is providing the host with protocols like HTTP and FTP.

Transport layer is responsible for the "end-to-end" communication, from sendting data to recieving data.

Network layer is responsible for moving the data from one computer to the next, but isn't that already done in the "transport layer"?

Link layer is responsible for transmitting the bit into a phycical signal. But didn't the "network layer" do that before reaching this layer?

So... What is the actual connection? If I am at Host A, and sending a package, let's call it Package A, to Host B. Then what is happeing?