How are devices represented in UNIX?
All devices are shown by files called special files that are located in /dev directory. Therefore, device files and other files are named and accessed in the similar way. A 'regular file' is just an ordinary data file in the disk. A 'block special file' determines a device with characteristics same to a disk (data transfer in terms of blocks). A 'character special file' shows a device with characteristics same to a keyboard (data transfer is by stream of bits in sequential order).