Hypertext Transfer Protocol (HTTP) was the first application layer protocol to be secured with SSL. All URI’s for pages fetched via HTTP over SSL/TLS begin with https:// to distinguish them from non-secure HTTP URI’s. The HTTP client makes a connection to the server and negotiates an SSLv3/TLSv1 connection. The negotiated connection is then used in place of TCP to transmit the data. The only other thing needed is the port number which IANA has assigned HTTPS connections port 443.

RFC 2818 Standard