Entrypoint.request.duration vs backend.request.duration

We're collecting Trafeik metrics in DataDog, and trying to set up some dashboards to monitor request time. I am confused as to what exactly entrypoint.request.duration measures, as opposed to backend.request.duration. I have not been able to find the answer in any of the documentation, and the raw metrics I can get from Prometheus do not match the names of the metrics that appear in DataDog.

Any help would be greatly appreciated. Thank you!

What version of traefik are you using? I guess 1.7.
Backend is removed on v2 and replaced by service metrics.
The main difference its that backend metrics has the backend labels so you can get the details per backend while entrypoint will only do for the entrypoints you defined, http and https for example.