Proper name fora Carausel unit

What is the name of a caraosel in which only one image is visible and the stack of images change in one frame?

That would just be a normal slider.

I need to find a theme where there is a header and beneath the header there is a frame with changing images, and then the usual right and/or columns.

Note that while many themes may come with a basic header slider, if you want to be able to create multiple such sliders (perhaps on different pages), layer text on the images, slide entire pages/posts (not just images), use fancy transitions/animations, and have a generally more interactive slider experience, you’ll typically have to use a dedicated slider plugin.