1. Deployment and Scalability: AWS Greengrass is designed to enable local computing for IoT devices, which means it allows the deployment of AWS Lambda functions on edge devices. This capability enables the devices to process data locally and reduces the need for constant connection to the cloud. On the other hand, Mosquitto is an open-source MQTT broker that facilitates secure messaging for IoT devices. It focuses on enabling communication between devices and does not provide local computing capabilities like AWS Greengrass.

2. Integration with Cloud Services: AWS Greengrass seamlessly integrates with various AWS services, such as AWS IoT Core, AWS IoT Analytics, and AWS Lambda. It allows easy data synchronization and communication between edge devices and cloud services, enabling sophisticated IoT applications. In contrast, Mosquitto is primarily designed for MQTT messaging and lacks the built-in integration capabilities with other cloud services offered by AWS Greengrass.

3. Authentication and Security: AWS Greengrass offers robust authentication and security features. It supports certificate-based authentication for devices and provides secure communication channels between devices and the cloud. It also offers automatic device registration and management, ensuring secure deployment and access control. Mosquitto, being an MQTT broker, supports basic username and password-based authentication, but lacks the advanced security features provided by AWS Greengrass.

4. Management and Monitoring: AWS Greengrass comes with a comprehensive management console that allows easy deployment, configuration, and monitoring of edge devices and Lambda functions. It provides detailed insights into device health, connectivity, and performance. In contrast, Mosquitto lacks a dedicated management console and monitoring capabilities. Management and monitoring of Mosquitto-based IoT deployments require additional tools and custom implementations.

5. Data Processing Capabilities: AWS Greengrass allows edge devices to process data locally using AWS Lambda functions. This enables real-time processing and analysis, reducing data transfer and latency. In contrast, Mosquitto focuses on efficiently transferring data between devices and does not provide native data processing capabilities like AWS Greengrass.

6. Vendor Lock-in: AWS Greengrass is a proprietary technology offered by Amazon Web Services, which may result in vendor lock-in for users. While it offers extensive features and integration with various AWS services, switching to a different cloud platform may require significant effort. Mosquitto, being an open-source MQTT broker, offers more flexibility and can be used with different cloud providers or on-premises setups.

In Summary, AWS Greengrass offers local computing capabilities, seamless integration with AWS services, advanced authentication and security features, comprehensive management and monitoring, data processing capabilities, but with potential vendor lock-in. Mosquitto, on the other hand, focuses on MQTT messaging, lacks local computing and advanced integration capabilities, has basic security features, requires additional management and monitoring tools, and offers more flexibility in terms of cloud providers.