A. Page or Navigation Flow indicator.
Much like a bread crumb or page indicator it shows a fixed number of steps and the user's current position. Its name can vary with what it's indication.
B. Carousel or picker.
Like @L. Mller said it is one of the variation of carousels. Typically the user's selection or position is in a fixed point or frame. The box can be considered as a visual treatment of the fixed point thereby emphasising the selection. This is not a mandatory visual treatment - and others treatments can work just as well, such as underlines, arrows, dots, spotlight, etc ...