Photos for OS X: Overview of importing photos and video
Import your photos and video into your photo library so you can organize and edit them with Photos. You can import photos and video in a variety of ways:
From iCloud: Turn on iCloud Photo Library on your Mac and iOS devices to access your entire library automatically. You can also use My Photo Stream to import your last 30 days of photos into your Photos library. For more information about using iCloud, see Access your photos and videos everywhere with iCloud Photo Library.
From cameras or mobile devices: You can connect a camera, iPhone, iPad, iPod touch, or other mobile device and import photos and video from the device. For more information, see Import photos from a camera or mobile device.
From storage media: You can import photos or videos saved on a hard disk or other storage devices. For more information, see Import photos and video from storage media.
From other apps: You can also import photos and video sent to you in an email or text message, or downloaded from Safari. For more information, see Import photos and video from other apps.
By default, imported photos are copied into the Photos library. If you prefer, you can store photos and video outside the Photos library—for example, in a folder on your Mac or on an external hard drive—and still view them in Photos. If you ever need to move content stored outside the library into your Photos library, you can do that, too. For more information about changing where your files are stored, see Change where Photos stores your files.