Photos is a photo management and editing application developed by Apple. It was released as a bundled app in iOS 8 on September 17, 2014—replacing the Camera Roll—and released as a bundled app to OS X Yosemite users in the 10.10.3 update on April 8, 2015. It was released for tvOS 10 on September 13, 2016.
Photos app running in OS X Yosemite
iPhoto is a discontinued digital photograph manipulation software application developed by Apple Inc. It was included with every Mac computer from 2002 to 2015, when it was replaced with Apple's Photos application. Originally sold as part of the iLife suite of digital media management applications, iPhoto is able to import, organize, edit, print and share digital photos.
iPhoto 9.6 running on OS X Yosemite