I want to upload my iPhone photos to iCloud but...

I want to upload my iPhone photos to iCloud but I don't want all of my iCloud photos on my iPhone. Is this possible?

If that’s what you want, then iCloud Photo Library is not the service for you. iCPL is designed to sync everything to everything. You can reduce the amount of storage used for Photos on a particular device by selecting to keep an Optimized library on it.

iCloud Photo Library basics, user guide