[GTALUG] Fedora 33 uses RAM for swap?

[Giles Orr]

A few days after upgrading the last of my machines from Fedora 32 to
33, I noticed my main machine has acquired a new disk:

NAME               SIZE FSTYPE      LABEL    MOUNTPOINT
zram0                4G                      [SWAP]

I didn't set that up, and I don't think it was there on F32.  So the
OS has, without asking, co-opted 1/4 of my 16G of RAM to use as swap
space.  This system has an SSD, so when I initially set it up (Fedora
27), I made a conscious decision to go without swap space.  I rarely
push the limits of 16G.

But now I'm in the situation that I have only 12G of RAM, so the
system will become memory-starved earlier ... and what will it do?  It
will go to swap.  Which is RAM anyway.  How does this help?  To me
this seems like adding complexity without adding utility.

Can someone please explain A) if I'm correct about this behaviour in
the first place, and B) why it's useful?  Thanks.

-- 
Giles
https://www.gilesorr.com/
gilesorr at gmail.com