I'm doing some development on a Raspberry Pi 3, and I was curious about a video I watched claiming to be able to "add more RAM" to the Pi using ZRAM. I know this isn't actually adding more RAM (since you can't just add more RAM without a physical addition), and it's more of a compression/swap file scheme, but I haven't been able to find a really good explanation of what is going on.

So for mine and others' sake and for documentation's sake, what exactly is going on here, and why is it (and is it actually) helpful?

(Please help with what tags to add to this question - I'm still new to Exchange and I wasn't sure)

I'm doing some OpenCV development on a Raspberry Pi 3, and I have found some information about using ZRAM on the Pi to try and boost its processing effectiveness. I know this isn't actually adding more RAM (since you can't just add more RAM without a physical addition), and it's more of a compression/swap file scheme.

This post has the best explanation I have seen so far, and explains that ZRAM is useful in some cases but not in others.

For my particular case, I am trying to run live OpenCV (Python) on a Raspberry Pi 3 B+ on a USB camera input. Would using ZRAM be helpful in my case? I would think an operation like this would be very CPU heavy, so it might be helpful.