An Intrusion Detection System (IDS) is a security tool designed to monitor network or system activities for signs of unauthorized access, suspicious behavior, or malicious attacks. It analyzes incoming and outgoing traffic, looking for patterns that may indicate threats such as hacking attempts, malware, or policy violations. When potential threats are detected, the IDS alerts administrators so they can investigate and respond. IDS solutions help organizations identify vulnerabilities and prevent data breaches, making them a crucial part of modern cybersecurity defenses.