"It decrypts that traffic, so you can see it in the log window, and then re-encrypts it to the destination server. Coming back the other way, it decrypts the server's responses, so you can see them in the log window, then re-encrypts them to complete the secure loop back to the browser. It's really quite amazing, and amazingly useful. Automation tasks that used to look like more trouble than they were worth -- for example, driving a HotMail or E*Trade account from a script -- suddenly look easy."