Device Types

• Device files aren't ordinary files -they do not represent regions of data on a disk based file system.
• Data read from or written to a device file is communicated to the corresponding device driver, and from there to the underlying device. Device files come in two flavors:
  • A character device represents a hardware device that reads or writes a serial stream of data bytes. Serial and parallel ports, tape drives, terminal devices, and sound cards are examples of character devices.
  • A block device represents a hardware device that reads or writes data in fixed-size blocks. Unlike a character device, a block device provides random access to data stored on the device. A disk drive is an example of a block device.