Processing and storing data in the local network in combination with the cloud (the Internet). The fog model pertains to the massive amounts of data generated by sensors in machine-to-machine computing (M2M). For example, offshore oil fields and refineries can generate a terabyte of data per day. An airplane can create multiple terabytes of data per hour. These capacities would strain communications networks if all the data were sent over the Internet to a central datacenter for processing.
Router giant Cisco coined this term to support the Internet of Things (IoT) with its IOx platform (Cisco's IOS router operating system and Linux operating system). Decisions are made in the routers at the edge of the network, and transactions that do not need immediate responses can be stored and processed locally or delivered to the cloud at off hours.
Close to the Ground
The "fog" name was chosen because natural fog is near the ground and away from the clouds. See Internet of Things