Linux Kernel Module Programming - 05 Introduction to Device Drivers
This video provides very elementary information about device drivers.
I talk about what a device driver is and what it is useful for. Also, a quick overview of major and minor numbers are covered.
Though it is not covered by the video, i should mention that there are two types of device drivers: character type device drivers and block type device drivers.
Character type device drivers are the most popular and are almost representative of the type of device drivers out there. Block type character devices are used more for storage items (sd cards) and write information in blocks. Character type device drivers write information in as many or in as little bytes as needed.