Hypertext Transfer Protocol
The World Wide Web (WWW) is one of the most commonly used services on the Internet. The Hypertext Transfer Protocol (HTTP) is a text-based application layer protocol that makes it work. All web browsers and web service applications use HTTP to communicate with each other over the Internet. A web browser or standalone application opens a connection and sends a request to the web server. The web server services the request and closes the connection to the web client.
HTTP is a stateless protocol.
You cannot find any information about persistent connections in the HTTP 1.0 specification. However, in essence, it was unofficially added to an existing protocol via the following additional header to the request: