AWS Shield vs Castle: What are the differences?

Developers describe AWS Shield as "Managed DDoS Protection". AWS Shield is a managed Distributed Denial of Service (DDoS) protection service that safeguards web applications running on AWS. AWS Shield provides always-on detection and automatic inline mitigations that minimize application downtime and latency, so there is no need to engage AWS Support to benefit from DDoS protection. On the other hand, Castle is detailed as "Track security events or any unstructured data from your web backend or mobile app, and Castle will look for anomalies". Castle looks for suspicious login patterns without bothering the legitimate user nor the site administrator. The fully-automated anti-hijack engine identifies potential account compromises based on where the user logs in from and how they navigate the site.

AWS Shield and Castle can be categorized as "Security" tools.