In the UK the eggs in the supermarket tend to be out on the shelves, but many people stick them in the fridge when they come home.
Eggs in the UK don't necessarily need to be refrigerated, but they do need to be stored in a cool place, and with many houses having their heating on it's just safe to have it in the fridge, and it's recommended by the UK Food Standards Agency.
But when it comes to using your eggs, a former Great British Bake Off contestant has said you should never use them straight out of the fridge.