Cat litter boxes are no exception, you can choose from a wide variety of shapes. You can practically classify them into three groups, open, semi-open and closed. All three perform their functions very well but some allow you to keep your home more odour-free.
Open. The container has only a bottom lid to store the litter. It's almost like a plastic tray with a small door for the cat to enter through. It doesn't reduce odour as much since it's not covered, but it does allow the litter to stay in one place.
Semi-open. This litter box has a top lid, which has an opening for the cat to enter through. There are variants in which the opening is on the side of the box. Odours are reduced due to the lid but not 100%.
Closed. Closed litter boxes have a top and bottom lid, with a transparent door in the access opening through which the cat can enter to use the litter. They retain most of the odours as the door does not allow them to escape except when the cat goes in and out of the litter box.