[pabloescobyte]

Probably using a QMK firmware-based keyboard where you can access different layers and shortcuts.

I'm using one right now (though mine runs off ZMK which is similar but wireless) which is a split with just 42 keys. The rest--numbers, symbols, function keys, etc. are all under layers. The layout is dynamic because holding down different keys makes the layout 'change' as you do so. Holding down the left spacebar and pressing 'Z' sends 'F1' to the computer while holding down another key on the right half turns my WER/SDF/XCV keys into a Numpad, etc.

[b112]

Side effect, no one knows your passwords, even if they watch you type!

[layman51]

I have never heard of "left spacebar" before. Sounds very interesting. So there can be two different spacebars on your keyboard?

[leereeves]

Some ergonomic keyboards are split between to the two hands (usually attached, but not always) and have a spacebar key for each hand.

But I always thought both keys sent the same signal to the computer.