What is this line down the side of my iPhone screen?

If you look at this picture, down the right of the screenshot (just to the right of the 3, the 6, and the 9) there's a thick line that goes from the very top of the screen, to the very bottom. What is this?

Also, it isn't the background picture. It does this with all the pictures.
What is this line down the side of my iPhone screen

I don't see it but I think it is dead pixels

It is dead pixels next time take the picture of the phone itself and not just a screenshot from the phone because pixels wouldnt effect the image that is displayed or captured just viewed thru the screen itself