for the lower three layers of the ISO Open System Interconnection model, what are the network device that operate each layer and their explaination?
Routers work at layer 3 and switches work at both layer 3 (network) and layer 2 (Data Link)
Sounds like homework... You should go read about the OSI then come back with specific questions for clarification.
check out this OSI model: http://studynotes.net/OSI-model
search google for keyword: "OSI layers with examples"