What is designed to detect, but not prevent, an attempted intrusion?

An Intrusion Detection System (IDS) is specifically created to monitor network traffic and identify potential intrusions or breaches in security. It analyzes patterns and activities on a network to detect anomalies that may indicate an unauthorized attempt to access resources or information. The key aspect of an IDS is its focus on detection rather than prevention; it alerts administrators to potential threats without actively blocking or preventing those threats from occurring.

This is different from other systems such as an Access Control System (ACS), which is focused on restricting access to certain resources based on pre-defined permissions, thus actively preventing unauthorized access. A Security Alarm System (SAS) may also alert individuals to security breaches but typically requires physical environmental triggers. Lastly, a Surveillance System (SS) generally focuses on monitoring and recording activities to provide evidence but does not serve the purpose of detecting intrusions in the same proactive way as an IDS does.