The KQL editor is a relatively new feature in Microsoft 365 that makes it easier to compose queries to find email and documents in content searches, core eDiscovery, and advanced eDiscovery. Although it’s not perfect, the KQL editor helps compliance managers to perfect queries and resolve syntax errors. Human intelligence is still needed to make sure that everything works!
https://office365itpros.com/2022/02/10/kql-editor-content-searches/
