So, I guess cookies are pretty popular items on the Internet. An Internet cookie is information stored by your Web browser to track or verify information used during a session with a world wide Web site. It's necessary because the normal method of interacting with a WWW page is that your browser connects to the Web site, downloads the page and its graphics, and then disconnects. Normally, there is no continuity between sessions. The meat of the cookie Cookies are handy things when you want to use the Web to conduct a multi-step transaction.
Shopping is a good example.
Imagine yourself at the grocery store. If every question is a new transaction, it is difficult to efficiently accomplish your ultimate goal. A more reasonable model for shopping is that you use a container like a shopping cart to store the items you intend to purchase, and then you retrieve them at checkout time. That information is stored in a cookie. Not surprisingly, many Web-based vendors use the analogy of the shopping cart when allowing you to add items to your intended purchase list.