What is the difference between photo stream and icloud photos? I have both files on my laptop
Each of them comes with their own advantages. Advantages of Photo Stream:
- Does not use your iCloud storage
- Only stores your most recent 1000 photos or the last 30 days of images
- Does not upload and sync videos
On the other hand, here is the advantages of iCloud Photo Library:
- Stores all your photos and personal video
- Uses your iCloud storage
- Stores full-resolution photos
If you want to see a good article about the whole difference, you can check this link.
Photostream will use an internet connection and copy photos to your other computers/devices so you have a backup that way and they are available on other devices that way. I actually use Photostream to save photos from my iPhone to my computer (I periodically move them from the Photostream folder on my computer to different folders and then I can delete them from my phone). It's not limited to 1000 that way if it's on your computer. Unfortunately Photostream does not transfer/sync your videos though, so I have to copy those off manually, argh.
iCloud has served primarily as a backup, and now there is an iCloud Photo Sharing which allows you to have better access to the photos thru the cloud, also from your various devices. It uses your iCloud storage capacity so you might run out if you have a lot of photos on your device (I think most people will end up using more than the 5GB you get for free). My method above for clearing out my phone of older photos allows me to not go over my free storage in iCloud. One advantage to iCloud is that your phone will smartly not store the full photo file and instead store one sized for your device saving space on your device. However if you want to do edits and use the photo for other things, it's always best to work from the original larger size.
I have to admit, this stuff is getting really confusing. People probably end up buying more iCloud storage pretty often just because they don't know what else to do and their device keeps saying they are out of iCloud space. My advice is to figure out one way that works for you and know it and stick with it.