Is elk stack a SIEM?

Could you please clarify if ELK Stack is considered a Security Information and Event Management (SIEM) solution? While it certainly has components that can be Leveraged for log management and analysis, I'm interested in understanding if it fully encompasses the functionalities typically associated with a SIEM tool, such as real-time threat detection, incident response, and compliance reporting. Additionally, how does ELK Stack compare to other dedicated SIEM solutions in terms of its capabilities and limitations?