The firefox ng seems pretty quiet now, so I've added win10. It's also
win10 question anyhow.

>In alt.comp.software.firefox, on Fri, 17 Jun 2022 08:59:53 -0400, micky
><NONONOmisc07@fmguy.com> wrote:
>
>>A few years ago a new option in the Settings was created, roughly,
>> Don't load tabs until the tab is opened. -- or "visited".
>>
>>I can't find it now. Do they still have it?

It turns out, that is the default now. I guess not only did I like it,
but everyone else did too. it can be turned off but there are four
interelated settings in about:config and I didn't understand all of it,
so I'm not going to try to explain it.

So this leaves the 2nd half of my question, which is definitely also a
win10 question. (To see more about the first half, check the Firefox
ng for June 17, 2022.)

I mostly posted in order to ask the questions in the last paragraph.
A friend believes that every tab is using resources whether you have
looked at it or not during the current FF session. The same level of
resources as if you had looked at it. I think
a) it uses barely any resources, maybe 200 bytes, until you look at it
and Firefox then loads it,
b) I seemed to notice that even if you looked at it and it loaded, if
you looked at another tab or program and were gone for a few minutes, it
unloaded that previously loaded tab. Is that true? When unloaded,
does it goes back to 200 bytes and no cpu cycles??

AIUI, when FF is started or restarted, even if the tab was loaded
before, only a tab that one has selected and viewed in this FF session
will have its expected contents downloaded or loaded from the cache.

And that would mean that even if one has 10 windows with a total of 100
tabs, only one tab, or maybe 10 tabs (one for each window**) would be
using resources, mostly RAM and maybe CPU cycles (if anything within the
tab used cycles. Many urls use resources at the start, prefetching
links mentioned on the page, but that doesn't take long. Other tabs have
little animated things or actual embededed videos, both of which take
cpu cycles, for downloading video and for playing video). And the other
90 or 99 tabs would only use the space it takes to specifify the URL and
a few bytes of background information, like which window, which tab,
what level of zoom is to be used to display it. Am I right?

**Which is it, One tab total, or one tab for each browser window?