That is the region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
That is the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
It includes the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south