Device management is a core function of an operating system (OS) that oversees the handling, allocation, and efficient use of hardware devices such as printers, disk drives, input/output (I/O) devices, and peripheral components.
- It ensures that devices are accessible, operate correctly, and share system resources without conflicts.
Classification of I/O Devices:
- Machine Readable or Block Devices
- User Readable or Character Devices
- Communications Devices
1.) Machine Readable or Block Devices
A block device is one with which the driver communicate by sending entire blocks of data.
- Data is read/written in blocks of a fixed size.
- Often used for secondary storage.
Examples:
- Hard disk drives (HDDs)
- Solid-state drives (SSDs)
- Optical drives (CD/DVD/Blu-ray)
- USB flash drives
2.) User Readable or Character Devices
A character device is one with which the driver communicate by sending and receiving single characters.
- Data is transferred character by character (or byte by byte).
- Sequential access, often without buffering.
Examples:
- Keyboards (input)
- Mice (input)
- Monitors or screens (output)
- Printers (output)
- Serial ports
3.) Communications Devices
Communication devices facilitate the transfer of data between systems or networks.
- They enable data exchange between computers and other devices, either locally or over the internet.
Examples:
- Network Interface Cards (NICs)
- Modems
- Routers
- Bluetooth adapters
- Wi-Fi adapters
