There are several main supermarkets in the UK with each differing on price and quality of food. These days, to save yourself the hassle of actually going to the shop, walking round and then carrying your food and groceries back, you can simply shop online. It saves you time and effort and can also save you loads of money. Online it is far easier to make sure you get the best deal, by using a comparison site to compare the price of your average shop between all the different supermarkets.