A cookie is a small text file that is stored by the computer when a website is visited by a user. The text stores information that the site is able to read when it is consulted at a later time. Some of these cookies are necessary for the proper functioning of the site, while others are useful to the visitor because they are able to securely store e.g. username or language settings. The advantage of having cookies installed in the your pc is that you no longer need to fill in the same information every time you want to access a previously visited site.
It is possible to modify the browser to disable cookies through a very simple procedure.
Warning: by disabling cookies, both username and password will no longer be stored in the login box of the site.