Session cookies allow users to be recognised on the website, in a way that any changes made are maintained while you are browsing on the website. In this way, you will not be asked for any information you have given previously. The most common example of this is the shopping basket function on any e-commerce site (online shop). When you visit a page of a catalogue and you select some items, the session cookie will remember your selection so that when you come to make the payment, your shopping basket will contain your selected items. Without session cookies, if you click on CHECKOUT, the new page would not recognise your previous activity on the previous pages and your shopping basket would always be empty.