Azure Monitor metrics vs logs, and diagnostic settings that send resource logs to a Log Analytics workspace

Azure Monitor is the platform service that collects, stores and analyzes telemetry from Azure resources, operating systems and applications. Almost everything it does rests on two kinds of data: metrics and logs. Knowing which is which, what is collected automatically, and what you must switch on yourself answers a large share of monitoring questions on the exam and saves you from discovering, during an incident, that the data you need was never captured.