He thinks that it should be better to design an speaking server as special kind of terminal. Application will print an output to terminal such as all other applications do but some special escape seqences will be passed to an speaking server. It will read an application's output, have history, that should be handled by user. So application will have just normal unreaded output to screen and it will be able to comunicate with server trought an socket. There is also some other differencies, but they are quite small.
Servers seems to be identical in a function.