Fog is an upcoming architecture for computing, storage, control, and networking that distributes these services and functions closer to end users along the cloud-to-things continuum. As the Internet of Things (IoT) is taking it's baby steps in the real world today, we can already see and predict various unique requirements and challenges it creates, which the existing architectures currently, or in future will, fail to meet. Fog is a very general architecture, which aims to comprehensively support emerging applications like IoT, 5G networks, and embedded AI by filling the technological gaps in existing computing and networking architectures. Fog includes both data and control plane, wired and wireless networks, spans hardware and software, and resides on the edge and access networks as well as among end users.

This survey paper\cite{Chiang_2016} summarizes the need, opportunities and challenges of fog, focusing primarily in the networking context of IoT.