iCloud Photos on multiple devices - will it end up jumbling everything together on icloud?

Okay, so here's the deal, up until now the only Apple device I've owned is an iPhone, but recently I bought myself an iPad, and rather than backing it up via iTunes, I decided to exclusively back it up through iCloud.

All well and good, especially with turning on iCloud Photos, this way no matter what, my photos on my iPad are backed up at all times, but then I thought, why not take advantage of this and also turn on iCloud backup on my iPhone.

I have yet to do this because of one major question that I haven't been able to find an answer for.

Basically I'm signed into the same Apple ID on both devices, because sharing /some/ stuff between the devices makes a lot of things easier (like contacts, calenders and so on, but not apps, i don't need all the many, many apps i have on my phone, on my ipad), but now I'm wondering, if i turn on icloud backup on my phone, and turn on icloud photos on my iphone, will that end up mixing up all the photos from both devices together, or will they have 'separate' folders?

I.E. If I log into icloud.com right this moment, it has all my ipad photos, but if i turn on icloud backup and icloud photos on my phone, and it starts uploading all my photos to icloud, will the photos from both devices end up all jumbled together, or will there be separate folders/sections for each device and whats been backed up to icloud?

Any help would be appreciated! :D