Simple definition
sysfs exposes Linux kernel device and driver information through a virtual filesystem under /sys.
Purpose and use
sysfs exposes a representation of kernel objects, devices and relationships, usually under /sys.
How does it work?
Attributes reveal selected state and, where supported and authorized, allow parameter changes.
Example and verification
For a device, correlate its sysfs path with kernel events and udev properties.
Points to watch
Entries are not all ordinary configuration files; a write can have an immediate system effect.
In short
sysfs interfaces with kernel objects and complements procfs.