The concept of the fog

Another edge computing facet of an IoT system architecture is known as the fog. The OpenFog Consortium released in 2017 a reference architecture (https://www.openfogconsortium.org/wp-content/uploads/OpenFog_Reference_Architecture_2_09_17-FINAL.pdf), in which they defined fog computing as:

A horizontal, system-level architecture that distributes computing, storage, control, and network functions closer to the users along a cloud-to-thing continuum.

Fog nodes are, as you would expect, placed nearer to edge devices in an IoT architecture. This allows for data analytics nearer the edge, and decision-making with minimized latency (minimized reach-back to the cloud).

Of course, the cloud still plays a role in these architectures, although cloud services are used for longer term, less cyclical data storage and more robust processing capabilities than are feasible at the edge or in the fog.

Fog computing allows data captured by IoT devices to be processed nearer to the edge. This...