Where are the photos located in iPhone are using photo stream and capturing photos using camera see the articles Overview of importing photos and videos into Photos on Mac - Apple Support
- Import photos by connecting a variety of cameras and mobile devices to your Mac: Connect a camera or other mobile device and import photos and videos from the device. See Import photos from a camera or phone.
See the section of of my photo stream paragraph in the article About iCloud Photos and My Photo Stream - Apple Support
As per this article My Photo Stream - Apple Support
How My Photo Stream works with iCloud Photos
My Photo Stream uploads your most recent photos (except Live Photos) so that you can view and import them to all of your devices. Photos are stored in My Photo Stream for 30 days. iCloud Photos uploads all of your photos and videos to iCloud and keeps them up to date across your devices.
If you turn on both My Photo Stream and iCloud Photos on an iPhone, iPad, or iPod touch, photos that you take with that device upload to both iCloud Photos and My Photo Stream.
If you use another device with the same Apple ID that has only My Photo Stream turned on, photos that you take on that device upload only to My Photo Stream. They don't appear on any devices that have only iCloud Photos enabled.