Ventoy is an OS.
It's a live Linux that boots from the USB stick you format/image with the ventoy tool. The rest of the space on the USB stick is configured to be essentially a standard USB drive.
The live Linux's sole purpose is to boot another image stored on the USB stick.
So, once you have "ventoy"d a usb stick, you can plonk gparted live iso, Ubuntu, Debian, Eos, W10, W11... whatever isos you want. When you boot from that USB stick, you get the ventoy menu screen and select the iso you want it to continue to boot.
Oh yeh, saved my skin a few times.
And you can use it like a normal USB stick once your OS is up, so you can have some installers on there to speed things up
Ventoy is an open source tool to create bootable USB drive for ISO/WIM/IMG/VHD(x)/EFI files. With ventoy, you don't need to format the disk over and over, you just need to copy the ISO/WIM/IMG/VHD(x)/EFI files to the USB drive and boot them directly. You can copy many files at a time and ventoy will give you a boot menu to select them.