In this illustration, the Internet appears as a cloud and is surrounded on all sides by a series of desktop computers, seven in total, and one server. To the left of the server is a cookie file, labeled "File: F." A black arrow points from the server to the Internet, and is labeled "us." Each computer has an arrow pointing from the computer towards the Internet, and an arrow pointing from the Internet towards the computer. Each arrow is labeled. Moving clockwise from the server, we see a series of computers. For the first computer, the arrow pointing to the Internet is labeled "u1" and the arrow pointing from the Internet is labeled "d1." For the second computer, the arrow pointing to the Internet is labeled "u2" and the arrow pointing from the Internet is labeled "d2." This pattern continues for computers three, four, five, and six. For the seventh computer, the arrow pointing to the Internet is labeled "uN" and the arrow pointing from the Internet is labeled "dN."