The Photos app on the Mac has four different views when you are viewing your Photos library. You can view them by years, months, days, or all photos. When you view them by years and open a specific year, the Photos app opens to the month view. From the month view, it will open to the day view. When viewing your photos by day, the Photos app shows you the best photos and videos from that day based on it’s own algorithm. To view all your photos you need to select All Photos. See how this all works in the video for viewing your photos and videos in the Photos app on the Mac.