arduino ethernet reference

If we look at http://arduino.cc/en/Reference/Ethernet we can see that there are two kinds of client and server objects. For example there is “Client” and “EthernetClient”. The second one has been introduced in arduino IDE1.
My question is: why now both object are present on the ethernet page? Is the “Client” only the old version and someone forgot to delete the page or to write “this is for ide<1”?
I have tried to initialize both objects in arduino IDE1 and the complier give me no error so why to use one or the other?

Another point: in the examples why sometimes address are declared as “byte ip={xxxx}” and sometimes as “IPAddress ip(xxxx)”?
Thanks

Another point: in the examples why sometimes address are declared as "byte ip[]={xxxx}" and sometimes as "IPAddress ip(xxxx)"?

Interesting question as various example code may use one or the other. I haven't seen any real explination of the difference between the two or how they are used by the ethernet librarys.