One of the key features that Google has been touting with its smartphones lately, has been the fact that they are able to store an unlimited amount of photos at their original resolution in Google Photos. Typically storing photos at their original resolution would count against your Google Drive storage (of which every user gets 15GB for free). But apparently, it's only unlimited until 2020, at least according to the fine print on Google's website (as well as in its presentation earlier today).
Google Photos does offer up unlimited storage at "high resolution" which is equivalent to 16-megapixels. Which is going to be high enough for photos taken with the 12-megapixel camera on the back of the Google Pixel 2 and Pixel 2 XL, so it's not that big of a deal, but it is an interesting thing for Google to do. It does, however make sense. It costs Google money to host your photos in Google Photos, and if you haven't bought a new phone in 3 years, they are going to be losing money. So it's basically a way to get you to upgrade to a new phone every few years, if you want to keep uploading photos in their original resolution.
With Pixel and Nexus smartphones not having a micro SD card slot for expanded storage, Google Photos has become a life saver for many people. Making it easier for users to upload their photos and free up storage on their device, and also keep all of their photos just a few taps away in the cloud. Since Google Photos does make it easier to go ahead and store all of your photos in one place. Additionally, Google Photos has a ton of other unique features, like the ability to automatically enhance your pictures, add different filters to them, and even create stories from different trips and such. It's a really great service that everyone should be using, since it is indeed a free service from Google. All users are able to upload unlimited photos in high resolution, and those that want to do original resolution will see the storage taken from their Google Drive storage, which users are able to upgrade, up to 10TB if they really wanted too.