Processes
nsurlsessiond
Handles background downloads and uploads for macOS and apps.
What it is
nsurlsessiond performs network transfers that continue in the background: iCloud sync, App Store downloads, software updates, and transfers started by other apps.
If your network seems busy and you can't tell why, nsurlsessiond is often the process doing the work.
Should you worry?
Not usually. Heavy use means something is downloading or syncing.
What you can do
- Check iCloud, Photos and the App Store for transfers in progress.
- Watch Activity Monitor's Network tab to see how much it's moving.