This works because block devices like /dev/sdX are just files. If you cp a file onto another file, it overwrites the data of the destination with the source. A block device represents the device itself, not the filesystem; if you wanted to put the ISO inside the filesystem, you’d have to mount it first.
The cp command will write the ISO file directly onto the device. This is the official way that is recommended by Debian:
cp debian.iso /dev/sdX
Source: https://www.debian.org/releases/stable/amd64/ch04s03.en.html
Woah…
Damn I’m sorry for questioning this method, I didn’t know.
This works because block devices like
/dev/sdXare just files. If youcpa file onto another file, it overwrites the data of the destination with the source. A block device represents the device itself, not the filesystem; if you wanted to put the ISO inside the filesystem, you’d have to mount it first.