What does "last visited" really mean?

[DubWolf 17,139]

I'm sort of confused with what it means; it says a user was last active say, 16 minutes ago, but you notice this after they recently sent you a message, so really they weren't active just 16 minutes ago, but rather much more recent than that...

Is this some bug?

[Ashen Pathfinder 16,160]

@Wooly Wolf

Just letting you know this was moved to Site Questions.

Thanks.

[Hierok 11,831]

I'm curious too. I thought always the forum is to big to keep track on it, but I highly doubt it. 

[Rikifive 23,886]

It's not always accurate, that's true.

That value changes every time user loads or refreshes the page. For example, if you'll get to a thread, that I'm reading for 30 minutes, it will be showing, that I was last active 30 minutes ago, even though I'm still reading it, unless I was changing pages in meanwhile.

The same as the 'Currently' status (shown below 'Last Visited' when online) can be inaccurate. For example, I'll go to a thread and then go to the main page in a new tab. It will be showing, that I'm currently on the main page, even though I closed that tab and I'm reading the thread, because the home page was the last thing I've requested from the site.

The true question is - Does 'Last Visited' value update when sending a message or making a post? Doing this doesn't refresh the page, just adds a reply, so it may be the possibility. That wouldn't be a bug then, but just how it works, though I can be mistaking.

Correct me if I'm wrong.