AWS Greengrass is a form of edge computing service that extends the cloud's functionality to your IoT devices by allowing data collection and analysis closer to its point of origin. This is accomplished by executing AWS Lambda functions locally on the IoT device itself, while still leveraging the cloud for management and analytics purposes.
How does this help a business? Well to start with, using AWS Greengrass you are now able to respond to locally generated events in near real time! With Greengrass, you can program your IoT devices to locally process and filter data and only transmit the important chunks back to AWS for analysis. This also has a direct impact on the costs as well as the amount of data transmitted back to the cloud.