Open telemetry works with all the three signals i.e. it help in generating all the three signals while Jaeger only focuses on one signal (traces).

The second key difference is Jaeger doesn't worry about generating data. It's more focused on the UI visualization long term storage of traces data while OpenTelemetry primarily focused on generating traces data.

Detailed blog with complete write up: https://signoz.io/blog/opentelemetry-vs-jaeger/