It would be a WHOIS nameserver lookup. You can use this website address, choosing the last of the three choices, to find information about an IP address.
http://www.internic.net/whois.html
The IP address comes from the internet service provider. With my laptop computer, the IP address changes as I move from my home network out to a Starbucks, a library or someone else's open wi-fi router.
The PING command is used to check the health of your internet connection. So you PING yahoo.com from your own computer to see how the ping is sent and received. It looks like this:
C:\Documents and Settings\USER>ping yahoo.com
Pinging yahoo.com [206.190.60.37] with 32 bytes of data:
Reply from 206.190.60.37: bytes=32 time=228ms TTL=55
Reply from 206.190.60.37: bytes=32 time=144ms TTL=55
Reply from 206.190.60.37: bytes=32 time=145ms TTL=55
Reply from 206.190.60.37: bytes=32 time=145ms TTL=55
Ping statistics for 206.190.60.37:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 144ms, Maximum = 228ms, Average = 165ms
If there was a problem with my internet connection, then the screen readout would show that packets had been lost, or the PING connection would have failed entirely.