What are transmit/receive buffers?

[Korialstrasza]

My file server's buffers are
Transmit: 512
Receive: 512

and my computer's:
Transmit: 128
Receive: 256

What do these mean? Can they be optimized?
Thanks!

 

[Xipher]

Can we get some context? Are these in relation to your NIC configuration or TCP/IP settings in your OS?

 

[Korialstrasza]

NIC configs