About Common Register and Socket Register

As i am new to the iEthernet controller W5500 chip set so need help to get understand about the common and socket registers, like how those registers can be used when? and where? with TCP/IP protocol.
as i show in datasheet there are 8 sockets in the chip set, if i want to make socket 0 as client and rest of the sockets(1to7) should be server, to make out this what? may be the procedure to get it down with this process.

Sources of information for you are datasheet and sample projects which you can download from various sources on the internet. Check WIZnet libraries provided on the GitHub.

Thank you Eugeny