Exactly what is the difference between devfs and sysfs? Both seem to maintain a list of hardwares attached to the system. Then why the need for 2 separate fs even arose? As far as I can get /sys maintains somewhat "raw" list of devices(like "ser0"). Udev acts on those devices, gets various informations and applies various rules to present them as recognizable names which are then mapped onto /dev(like "camera"). Is this the only reason? And then we mount the corresponding devices from the /dev fs(can't we do that from the /sys fs) into the /media fs.
I have read the answer at Difference between /dev and /sys/class?. But I cannot get the sys fs part where it states that
Sysfs contain the hierarchy of devices, as they are attached to the computer
Are the files in /sys not device node files? Then what type of files are they?