1. iCloud Photo Library stores pictures as long as there is enough space while Photo Stream only saves recent 1000 images or the latest 30 days of pics.
2. iCloud Photo Library supports not only images storage, but also videos uploading and syncing, but Photo Stream can only keep pictures.
3. The former allows full-resolution pictures stored on both the server and the device, which is not available for the latter.
Therefore, compared to Photo Stream, iCloud Photo Library, in my opinion, can be considered as a proof that Apple keeps enhancing user experience. Now, you can follow the guide below to upload your photos to iCloud Photo Library and view them on iCloud web page.
Note: You can use iCloud Photo Library to save your device space by selecting a storage mode. There are two modes optional:
Optimize iPhone Storage: all your original, full-resolution images and vedio will be uploaded to the cloud while device-size versions will be kept on the device.
Download and Keep Originals: all your original images and videos will be saved to both the cloud and your device.
Well, now let's figure out the problem that where we can go to get the synced album. Indeed, it is simple too.
Log in your account onto www.icloud.com and then click the "Photos" icon in the primary window. After entering the detailed interface, you can see all your photos classified into "Moments" and "Albums".
Via iCloud web, you can download, delete and mail any single picture, and the change will be also synced to other devices.
With iCloud Photo Library, people can manage their photos in a better way. But remember, this service only backs up iOS photos, so if want to back up other files, iTunes/iCloud or iOS Transfer will be your good choose.