Tracking a request’s flow across different components in distributed systems is essential. With the rise of microservices, their importance has risen to critical levels. Some proprietary tools for tracking have been used already: Jaeger and Zipkin naturally come to mind.
Observability is built on three pillars: logging, metrics, and tracing. OpenTelemetry is a joint effort to bring an open standard to them. Jaeger and Zipkin joined the effort so that they are now OpenTelemetry compatible.