Security Information and Event Management (SIEM) tools, software platforms that aggregate and analyze security logs from diverse sources to detect and respond to cyber threats. SIEM functionalities like threat detection, incident response, and compliance management, highlights popular SIEM tools such as Splunk and IBM QRadar, and discusses crucial factors to consider when selecting a SIEM solution, including scalability, integrations, and cost. The focus is on how SIEMs provide a unified view of an organization's security posture.