In the context of OpenTelemetry, what is a span?

A span is a fundamental concept in tracing within OpenTelemetry, representing a single operation within a trace. When an application executes multiple operations, such as handling requests or processing tasks, each of these actions is captured as a span. A span contains information about the operation it represents, including its start time, duration, any associated metadata (like tags), and context about its parent and child spans.

This hierarchical structure allows for visualizing and understanding the flow of requests through various components of a system, making it easier to identify performance bottlenecks or failures in complex, distributed applications. By breaking operations down into spans, developers and operators can get detailed insights into how different parts of their systems interact and the time taken for each operation, which is crucial for optimizing application performance and troubleshooting issues.