If its just a small/home network, chances are the IP addresses start with 192.168.0.x with subnet mask 255.255.255.0.
Medium-larger sized networks usualy have the 10.0.0.x and subnet mask 255.0.0.0. That address could also be comonly used for the broadband/adsl modem's internal IP address.
The internet IP address depends on what your ISP gives you.. and they usualy have a pool of numbers to choose from, and some are static, others automatic.
The last digit(s) on the address just signifies a independant machine type of thing.. Its like a house address, say, 32 Somewhere Avenue, Nowheresville.
The 32 is like the 192.168.0.
32. The rest of it is the address: somewhere ave etc. So the last digits you mentioned means nothing without knowing the whole address.. but dont post it here if its not the 10. or 192. numbers, just in case
As i said, you may be able to ping something, but whether you can connect to it or unless you know the exact IP address is another step of troubleshooting. It could be that the ethernet adaptor with that address is on standby mode or something, and hence you can "talk" to it, but the machine can be off or on i'm not sure.
you can try opening up IE or explorer, and typing the IP address in there.. if you have the passwords and such for the other pc...
Good start for reading up on it is
http://en.wikipedia.org/wiki/Ping
http://en.wikipedia.org/wiki/IP_address