ping can be used for a lot of things. I do use it a lot to test reachability and how my internet access is behaving.
Usually you just execute ping in your terminal and then hit Ctrl+C to see the summary as follows:
Hitting Ctrl+C will send an interrupt signal (SIGINT) to the process, making it to terminate and show ing the summary.
Once in a while you need to check a long ping run but don't want to stop it (because of the final stats). The way of doing it, is to send a SIGINFO signal hitting Ctrl+T while the process runs.
Check line 9 and 10 in the previous example:
and ping continues running!!!
References: Ping OS X Manual.