how to know the LAN connection in building the chat group

[kikiey]

Am new to the world of networking on LAN, i need help to get me in the right direction in creating a LAN Chat that has the capability to send file across the network. i want this chat to be able to handle more than 50 connections. how to connect to another pc in LAN connection? using ip address/ localhost or what? i have created client and server connection, but i dont get the connection between two pc. im trying to use localhost but it doesnt work. Any tutorials or sample code will do. thanks...

[adi12]

    make lan connection between two computer use of bus cable , ring cable,hybrid,star etc.............

[kikiey]

what connection can i use to make one computer is a server and another computer is a client? localhost or public ip or private ip?