Which directory contains device files on a Linux system?

• A. /dev
• B. /proc
• C. /sys
• D. /usr

Answer: (A)

Device files are the interfaces to hardware and drivers, and on most Linux systems they live in the /dev directory. These are special files—character devices that provide a byte-stream interface and block devices that provide random access to blocks of data. The kernel uses major and minor numbers on these files to determine which driver handles the device.

The other directories serve different purposes. /proc is a virtual filesystem that exposes runtime process and kernel information, not actual device nodes. /sys (sysfs) exposes kernel objects and their attributes for configuration and inspection, but it isn’t where device files are stored. /usr contains userland programs, libraries, and data, not hardware interfaces.