Google launched Google Photos for Android, iOS, and the Web. Google is declaring that Google Photos lets you backup and store “unlimited, high-quality photos and videos, for free.”
That said, Google Photos maintains the original resolution up to 16MP for photos and 1080p high-definition for videos. The app also stores compressed versions of the photos and videos in print-quality resolution.
And for Pros...
If the photographer wants to keep the images at full resolution, they can buy storage from Google. The first 15 gigabytes are free, and then it's $10 a month for 1 terabyte. (Assuming that the avg size of a proffesional photo is 40 or 50 MBs per picture, then a 1TB will hold around 20'000 photos)
Because Google Photos no longer relies on Google+, the company has given the team the green light to support other social networks. Users can post images to Facebook and Twitter, as well as messaging apps like Hangouts and WhatsApp.