Protocol
The first part of the URL identifies the application protocol. HTTP URLs start with the familiar http://. Other applications that use URLs to locate resources identify different protocols; for example, URLs used with the File Transfer Protocol (FTP) begin with ftp://. URLs that identify HTTP resources served over connections that are encrypted using the Secure Sockets Layer start with https://. We discussed the use of the Secure Sockets Layer to protect data transmitted over the Internet in Chapter 9.