What feature does AWS AppSync offer?

AWS AppSync offers real-time data synchronization, making it an essential service for applications that require immediate updates and data consistency across multiple clients. This feature allows developers to create rich, responsive applications by automatically syncing data between the backend and connected devices. With WebSocket connections, AppSync facilitates the push of updates to clients when data changes occur, enhancing user experience by ensuring that users always have the latest information without needing to refresh or manually check for updates.

In contrast, the other options do not align with the core capabilities of AWS AppSync. Static website hosting is typically provided by services like AWS S3 and Amazon CloudFront, whereas vulnerability scanning and patching are features more relevant to security-focused services like AWS Inspector or AWS Systems Manager. Video streaming services are not a part of AppSync's offerings; rather, AWS specifically provides services like Amazon IVS and AWS Elemental Media Services for video functionalities.