What is the role of an Intrusion Detection System (IDS) in network security?

• A. To monitor network traffic for suspicious activity and potential threats.
• B. To manage user passwords and authentication tokens.
• C. To filter and block unwanted traffic at the network edge.
• D. To perform vulnerability scanning on hosts.

Answer: (A)

An IDS is focused on watching network traffic for signs of unauthorized or malicious activity. It analyzes data patterns against known attack signatures and normal behavior baselines to detect threats, then generates alerts so security teams can investigate and respond. It provides visibility, logging, and incident triage, often feeding into a SIEM for correlation and forensics. This role is detection and notification, not credential management or traffic blocking. Blocking traffic is typically handled by firewalls or intrusion prevention systems, while vulnerability scanning is a separate activity that looks for weaknesses in hosts.