= What is fog computing

In the early days of digital computing, the computers themselves were big and expensive.
The few users there were in the world had to reserve time on a computer (and show up in person) to have their punchcards processed.
Systems called https://opensource.com/article/19/9/linux-mainframes-part-1[mainframes] made many innovations and enabled time-shared tasks on terminals (like desktop computers, but without a CPU of their own).

Skip forward to today, and we all know that powerful computation is https://opensource.com/resources/raspberry-pi[as cheap as $35 USD and no larger than a credit card] now.
And that doesn't begin to cover all the little devices in modern life that gather and process data.
Take a high-level view of this collection of computers, and you can imagine all of the many devices outnumbering grains of sands, or particles in a cloud.

It so happens that the term "cloud computing" is already occupied, so naming the network comprised of the Internet of Things (IoT) and other strategically stuated servers needed to be unique.
And besides, if there's already a cloud representing nodes of a data center, then there's surely something unique about the nodes intermingling with us folk outside that cloud.

== What is fog computing

The Cloud delivers computing services over the Internet.
The danger here, though, is that the data centers that make up the Cloud are big and relatively few compared to the number its potential clients.
This suggests potential bottlenecks when data is being sent back and forth between the Cloud and its many users.

Fog computing, by contrast, can outnumber potential clients without risking a bottleneck, because the devices themselves perform much of the data collection or computation.
It's the outer "edge" of the Cloud, the part of a cloud that touches down to the ground.

== Fog and edge computing

Fog computing and https://www.redhat.com/en/topics/edge-computing/what-is-edge-computing[Edge] computing are essentially synonymous.
Both have a strong association with both the Cloud and IoT, and make the same architectural assumptions:

* The closer you are to the CPU doing the work, the faster the data transfer.
* Like https://opensource.com/resources/linux[Linux] itself,  there's a strong advantage to having small, purpose-built computers that can "do one thing and does it well". (Of course our devices actually do more than just one thing, but from a high-level view, a smartwatch you bought to monitor your health is essentially doing "one" thing.)
* Going offline is inevitable, but a good device is able to function just as effectively in the interim and then sync up when reconnected.
* Local devices can be simpler and cheaper than big data centers.

== Networking on the edge

It's tempting to view Fog computing as a completely separate entity from the Cloud, but actually they're just two parts of the whole.
The Cloud needs the infrastructure of the digital enterprise, including public cloud providers, telecommunication companies, and even specialized corporations running their own services.
Localized services are also important, to provide waystations between the Cloud core and its millions and millions of clients.
Fog computing, located at the edge of the Cloud, intermingles with the clients, where they are located.
Sometimes, this is a consumer setting, such as your own home or car, while other times it's a business interest, such as price monitoring devices in a retail store or vital safety sensors on a factory floor. 

== Fog computing is all around you

Fog computing is built up of all the connected devices in our own lives: drones, phones, watches, fitness monitors, security monitors, home automation, portable gaming devices, gardening automation, weather sensors, air quality monitors, and much much more.
The data it's able to provide lends itself, ideally, to building a better and more informed future.
There are lots of great open source projects out there that are working toward improving health and wellness or even just to make life a little more entertaining, and it's all happening thanks to Fog and Cloud computing.
All of _our_ jobs is to make sure it https://opensource.com/article/20/10/keep-cloud-open[stays open].