Cookies are small text files that a web-site can use to store information. The cookies are stored on the client computer and are not maintained on the server. Cookies are normally used to hold details of customer profiles etc. obviating the need to re-register each time you return to a particular web-site.
You have complete control over cookies on your machine, you can choose to accept them or not, and you can simply delete them from your machine at any stage. In the case of this database if you choose not to accept the cookie or delete the cookie you will have to re-register the next time you vist the site.
By not maintaining this information on the server, your privacy is preserved.