After studying this chapter on cookies and sessions, it is important to recall the main focus of the text: databases. Databases provide ways other than cookies or sessions for builders of Web applications to retain information on the visitors to the site, or at least the ones willing to invest the time and have the trust to enter information into the system. Similarly, you have seen the trick of passing information in the query string of an address cited in a hyperlink. You now have the tools of data bases, query strings, cookies, and session information to use in your application, individually or in combination.
When deciding on whether to use sessions, you will need to estimate the upper limit on concurrent visitors to your Web site and consult with the server administration.