Confuse to connect my Arduino Ethernet Lan Shield to other PC

So then now I can connect one computer to send information to other PC using LAN...

How are you doing this? Specifically, how are the two PCs known to each other, and what software is running on each one.

But I confuse how I make that other PC can receive the data I sent

What data, sent from where? To where?

I have downloaded processing but no idea to make it

Make it what? Why did you download Processing.

No I am downloading scada and hope It makes me easier to connect using LAN...

It won't. Stop right now, while there is still disk space on your PCs.