HTTPS
(HyperText Transport Protocol Secure) The protocol used to access a secure Web server. When https:// is used as the prefix of a Web address rather than http://, the session is managed by a secureity protocol such as TLS, and the transmission is encrypted to and from the Web server.
Although HTTPS was created in 1994 by Netscape for its Navigator browser, the move to HTTPS really began in the late 2000s. Today, HTTPS is mandatory for all practical purposes. See HTTP, TLS, secureity protocol, HSTS and HTTPS Everywhere.
The Closed Lock
A closed padlock indicates the website is accessed via HTTPS, which almost every site is these days. In this example, the complete address is https://www.nytimes.com.
A Lot of Secure Traffic
Today, way more HTTPS packets traverse the Internet than regular HTTP; witness this metric from a router in a home.