Fog node

Definition
Fog nodes are

"intermediary compute elements of the smart end-devices access network that are situated between the Cloud and the smart end-devices. Fog nodes may be either physical or virtual elements and are tightly coupled with the smart end-devices or access networks. Fog nodes typically provide some form of data management and communication service between the peripheral layer where smart end-devices reside and the Cloud. Fog nodes, especially virtual ones, also referred as cloudlets, can be federated to provide horizontal expansion of the functionality over disperse geolocations."