What is a "Use Case" in SIEM?

The author of the post, a beginner in SIEM and cybersecurity, expresses confusion regarding the term "use cases" in the context of SIEM and Threat Intelligence. They mention having searched for definitions online and from professionals but received varied responses. The author wants to understand what it means to verify if a SIEM has integrated "use cases" or to develop a "use case," and asks if this is equivalent to "playbooks."