One of the goals of these protocols is to provide server and client authentication,
data confidentiality, and data integrity. Application-layer client/server programs, such
as HTTP (see Chapter 22), that use the services of TCP can encapsulate their data in
SSL packets. If the server and client are capable of running SSL (or TLS) programs,
then the client can use the URL https://... instead of http://... to allow HTTP messages
to be encapsulated in SSL (or TLS) packets. For example, credit card numbers
can be safely transferred via the Internet for online shoppers.