How does persistence record get timed out?

I know this is getting a bit off-topic but you said..

 

"The timeout counter starts when no connections reference the persist entry."

 

 

I have always been fuzzy about defining what a "connection" is in terms of peristence and OneConnect. What I mean is, if a client hit s a web page(dloads text and images) and then drills down to other pages, what is considered a new connection? Is it anytime the port number changes?