hops can be defined as the amount of jumps between you and somebody else. Example:
Me on server 1
server1 linked to server2
server2 linked to server3
server3 linked to server4
You on server4
The amount of hops on that example (if I understand how it all gets counted) would be 3:
1) Me/server1 to server2
2) Server2 to server3
3) Server3 to server4/you
Make sence now? it has to do with how servers are all linked together and the route chat has to go thru to get to people