A child span records the start and end of a significant activity nested inside another span. Nesting lets a trace represent an operation composed of smaller services or transactions as a hierarchy rather than a single undifferentiated event. section 3.6.7
Use child spans to preserve the composition of end-to-end work when a transaction crosses services or contains nested activities. The resulting trace can associate those activities with the same transaction context and its metadata. section 3.6.7
Within OpenTelemetry observability data:
- Logs capture traditional application logging. section 3.6.7
- Traces organize significant activities as spans, including nested spans. section 3.6.7
- Metrics measure resource or business values such as CPU use or transactions per minute. section 3.6.7
