Well actually I dont understand what you realy mean. With telnet, as you allready know, you can connect to another host, somwhere in the net or on the LAN and so on. After that, it depends on the tasks you want to accomplish. Also it's a question what OS you are on, on teh remote machine I mean.
The idea is, you should try to get familiar with the remote machine's OS.
Pls don't get me wrong, I don't want to offend you, I'm just curious.
Best,
badfinger