Photos in Windows 10

When I download in Windows 10 a picture from my Cloud storage, it appears on my PC screen with the title “Photos,” followed by the picture’s identification. (I am then able to photoshop the picture, and then copy/paste it in my Pictures folder in the PC.)

What I am very curious about is whether the above “Photos” is a built-in Windows 10 facility. I have not seen in the Control Panel or Settings any mention of “Photos.”