AWS IoT Greengrass lets you build IoT solutions that connect different types of devices with the cloud and each other. Devices that run Linux, including distributions such as Ubuntu and Raspian, and support Arm or x86 architectures can host the AWS IoT Greengrass Core. The AWS IoT Greengrass Core enables the local execution of AWS Lambda code, messaging, data caching, and security. Devices running AWS IoT Greengrass Core act as a hub that can communicate with other devices that are running Amazon FreeRTOS or have the AWS IoT Device SDK installed. These devices could vary in size, from smaller microcontroller-based devices to large appliances. AWS IoT Greengrass Core devices, AWS IoT Device SDK-enabled devices, and Amazon FreeRTOS devices can be configured to communicate with one another in an AWS IoT Greengrass group. If the AWS IoT Greengrass Core device loses connectivity to the cloud, devices in the AWS IoT Greengrass group can continue to communicate with each other over the local network. An AWS IoT Greengrass group may represent one floor of a building, one truck, or an entire mining site.