Google Photos can automatically back up your pictures from a number of sources to its online servers. These sources include a digital camera’s memory card, the desktop and your Mac’s Pictures folder. If you do not already have a Google account to use with the company’s slew of online services (like Gmail, YouTube, and Google Drive), you can sign up for one on Google’s site.
If you already have, say, a Gmail account, log in with your web browser and click the small square Apps menu icon in the upper-right corner. This opens a box showing all the available Google sites and programs, including Google Photos. If you use Google Drive, a link to Google Photos is in the menu on the left wide of the screen.
Then, download a copy of the desktop uploader program for Google Photos. The uploader is a small piece of software (available for Mac and Windows computers) that automatically grabs copies of the pictures it finds on your hard drive and sends them to your online Google Photos account.
When you open the uploader for the first time on the Mac, the program’s setup screens let you choose which photos and locations you would like to back up, including those from cameras and memory cards connected to the Mac. If you want to keep your photos in the original resolution, you may have to buy more storage space from Google if you use up your free allocation (usually 15 gigabytes).