Hypertext Transfer Protocol (HTTP) is application layer encapsulation used for information retrieval on the World Wide Web. The HTTP specification was developed jointly by the IETF and the W3C. In a URL, the prefix http:// indicates HTTP request/response traffic. Secure HTTP using Secure Sockets Layer (SSL) or Transport Layer Security (TLS). Secure HTTP traffic is indicated with the URL prefix https://.
See RFC 2616.