IoT, more specifically for this post, IIoT (Industrial Internet of Things) is probably the hottest buzzword today. The whole premise of IIoT is networked devices that are connected and interact and exchange data. In most cases, the networked device is also called an Edge Device. In IIoT an edge device is a device with network accessible actuators, sensors, and even moving assets (locomotives, cars, airplanes, ships, etc.).
Edge Computing is the ability to collect data (temporarily store it), filter, aggregate, and send data to the cloud or data center. Additionally, Edge Computing includes the ability to run analytics (make decisions) on the device without risking the latency of sending the data to the cloud for a decision and sending the decision back to the device for an action. This becomes VERY important when you factor in intermittent connectivity, low bandwidth (and/or high cost for additional bandwidth), immediacy of insights, and security related concerns.