A company wants to be sure their cloud infrastructure is secure but fully available. To ensure this, the company wants to observe and be alerted in the event of a security breach, but chose a…

XaaS (Everything as a Service) is a broad cloud service delivery model category and is not a security monitoring or alerting tool.

An Intrusion Detection System (IDS) monitors network traffic and system activity for suspicious behavior and generates alerts, but does not take automated action to block or stop threats. This passive posture keeps the infrastructure fully available because no traffic is dropped, while still notifying staff of potential breaches. Administrators retain full control to manually choose and execute a response for each alert, satisfying both requirements.

PaaS (Platform as a Service) is a cloud delivery model for hosting and developing applications and has no capability to detect or alert on security breaches.

An IPS (Intrusion Prevention System) automatically blocks or drops malicious traffic inline without administrator intervention, eliminating the ability to manually choose a response per alert.