# LVS Devices

## Device extractors and device classes

KLayout provides two concepts for handling device variety:

Device classes are device categories. There are general categories such as resistors or MOS transistors. Specific categories can be created to represent specific incarnations - e.g. NMOS and PMOS devices. Device classes also determine how devices combine.

Device classes are documented here: .

Device extractors are the actual worker objects that analyze layout and produce devices. As for device classes, there are general device extractors. Each device extractor produces devices from a specific class.

Device extractors are documented here: .