/devè la directory di file speciali o file (nello specifico directory) di dispositivi (HDD, SSD, etc.), i quali rappresentano le partizioni del sistema. Queste directory sono delle interfacce tra il file system e i dispositivi hardware che rappresentano.
Da tldp.org: “This may seem strange but it will make sense if you compare the characteristics of files to that of your hardware. Both can be read from and written to. Take /dev/dsp, for instance. This file represents your speaker device. Any data written to this file will be re-directed to your speaker. If you try ‘cat /boot/vmlinuz > /dev/dsp’ (on a properly configured system) you should hear some sound on the speaker. That’s the sound of your kernel! A file sent to /dev/lp0 gets printed. Sending data to and reading from /dev/ttyS0 will allow you to communicate with a device attached there - for instance, your modem.”