New concepts, including fog computing and edge computing, which in many ways appear to be similar, can be hard to define. And, sometimes, the explanation of differences can increase, rather than decrease, confusion.
Fog computing is the harder concept, some would argue, as it often is described as a framework or standard for edge computing. “Edge” computing includes both computing on an edge device as well as computing “close to” the edge device, but not at a traditional remote cloud data center.
The phrase local area network almost always occurs when “fog” is defined. And that is where some confusion can occur. In a traditional sense, the local area network is a privately-owned, indoor or campus-wide network separate from the public “access” network.
But in a more general sense, some might refer to the “local” area network as some intermediate point in the access, feeder or distribution portions of a public network (downstream of a central office, for example).
Some might say the fog concept involves computing where it makes most sense (remote cloud data center, computing somewhere in the access network, at a premises server or on an actual end user device.
For me, that works best. In cases where a former central office becomes an “edge computing center,” that is computing within the fog architecture. But so is edge computing at some other intermediate location between a single end user device or appliance and the place where the wide area network is encountered.
Just “where” that computing location occurs in a fog framework is somewhat indeterminate. So the phrase “local network” will cause some confusion, sometimes. Are we meaning the traditional “inside the building” private network, or what we know as the public network “access” network.
In the fog framework, that can mean either of those uses. Edge computing might occur at a server on the premises, outside the premises, or at the edge device itself.