Fog computing
Fog computing is a distributed architecture that places compute, storage, networking, and control functions between smart devices and centralized cloud systems.
What fog computing is
Fog computing is a distributed computing model that sits between smart end devices and traditional cloud or data-center resources. It moves some application logic, data processing, storage, control, and networking functions into nearby fog nodes instead of sending every task to a distant cloud.
How it differs from edge computing
The terms fog computing and edge computing overlap, and different organizations draw the boundary differently. In common use, edge computing emphasizes processing close to where data is created, while fog computing often describes a broader, layered, federated architecture across gateways, access networks, local servers, and cloud systems.
Fog nodes
A fog node is the practical building block of a fog architecture. It may be physical hardware such as a gateway, router, switch, server, or industrial controller, or a virtual resource such as a virtual machine or cloudlet. Fog nodes can work alone, in clusters, or as part of a hierarchy.
Why IoT systems use it
Internet of Things systems may produce large volumes of sensor and machine data across many locations. Fog computing can filter data, run analytics, support local control, enforce policies, and keep time-sensitive functions close to the devices that depend on them.
Cloud-to-thing continuum
Fog computing is often described as part of a cloud-to-thing continuum. Tiny devices may handle simple sensing or actuation, fog nodes may run local workloads and coordinate nearby systems, and cloud services may handle fleet management, long-term storage, model training, and global analytics.
Strengths
A good fog architecture can reduce request-response time, lower bandwidth demand, support mobility, keep some data local, and improve resilience when cloud connectivity is limited. It can also support real-time interactions in transportation, factories, energy systems, smart cities, healthcare, and media networks.
Challenges
Fog computing spreads infrastructure across many sites and ownership boundaries. That raises hard questions about interoperability, security, identity, software updates, observability, orchestration, physical tampering, data governance, and who is responsible when a distributed service fails.
Why it matters
Fog computing helps explain why modern computing is not simply device versus cloud. As connected systems become more real-time and geographically distributed, designers need intermediate layers that can make local decisions while still cooperating with larger cloud platforms.