Camera size changes depending on device size?

So I have noticed the size of the Cameras change And one of the biggest problems I had was that

The iphone 4 screen or something like the ipad made the screen a lot smaller on the horizontal side meaning the player with something like a big screen could see the sides that the player with iphone won't see

How do I fix this?

I want every screen to be consistent

I have a script where my camera changes to scriptable and shows a screen but people with smaller screens cannot see the edges of the camera horizontal side. Its either cut or they litteraly dont see the edges of the screen.