Get my photos on all my devices I want all my photos from icloud to appear on all my devices. I've turned on icloud onto all my devices but they are all out of sync. This is quite strange, is this expected behaviour?

I've read I might need to enable photo stream but not only is it not clear what photo stream is but it also seems to have limitations, for example, it is limited in how many it can sync.

With google photo is syncs and stores all my photos in the cloud and shows me all the photos on all my devices. Is there no such thing for apple?
You want to enable photo stream, and really every kind of sharing there is.  I personally don't use iCloud for photo sync, but instead I use DropBox with Carousel.  The reason for this is that Carousel has a much simpler interface, and automatically takes care of all syncing (provided you use the Carousel app for viewing photos).  You also can have more space to store (1TB or more depending on your plan, as much as 50GB for the free plan, depending on what you've done in it - I have 8GB)