Web managers can create some security for their materials by having the server control access to it. Servers can be instructed to screen who gets access to materials stored there. It is possible to restrict access to local users, for example. Only clients having the same local address as the server would be able to view restricted pages. Materials can also be protected by passwords.
Authorized users access the information only after supplying the secret password.
Servers can also be instructed to interact with users by requesting that they supply information before permitting access to pages. Users can be asked to fill out forms that identify them. The information is sent back to the server for recording and processing. A number of companies use these methods for commercial enterprises over the Web. You can purchase an item by supplying a credit card number for the transaction.