what IS wireshark

All,

Just passing through, but there are so many things about this site which, on first glance, seem to be so very cool, that I thought I'd make a comment. I got here by Googling 'wireshark'--I read a reference to it in a context that made me want to know more--but, getting here, I can't find a single thing that explains what wireshark is. The FAQs explain the rules of the forum very well, but there seems to be no FAQ about the software itself.

Now, I'll go back to Google and continue trying to find out what wireshark is.