Newer Macs running OS X Yosemite (v10.10.3) and later include Photos, Apple’s new photo management app. Photos works with your iCloud account, so you can store your photos online and then access them on any computer or device.
First steps with Photos
Open the Finder window, select Applications from the Finder Sidebar and then double-click Photos to open the app. Click the Get started button, then follow the setup instructions.
Photos will locate and import any existing photo libraries that are on your Mac. Be warned, however, depending on the size of your photo library, this process can take a long time.
iCloud Photo Library
During setup, you’ll be asked if you want to turn on iCloud Photo Library using your Apple ID. iCloud Photo Library keeps a single up-to-date photo library across all of your Apple devices.
Any photo that you take on your iPhone or iPad, or import into Photos on your Mac, is uploaded automatically to your iCloud storage and can be viewed on any device that’s linked to your iCloud account.
Import your photos
Once set up, Photos will prompt you to import your digital pictures from other sources. You can do this by connecting your digital camera, iPhone, memory card or hard drive to your Mac and then selecting photos or folders of photos and dragging them directly onto the open Photos window.
Alternatively, click File > Import from Photos’ menu bar and navigate to the drive or connected device, then select the photos you wish to copy.
Share your photos
Select the photos you want to share, then click the Share icon (a box with an up-arrow). The options you’ll see next include uploading to iCloud Photo Library, Facebook, email or Twitter, plus Messages to send them to an iPhone.