HTTP (Hypertext File Transfer Protocol) is a set of rules for exchanging files on the World Wide Web. HTTP defines how messages are formatted and sent, as well as the actions web servers and browsers should take in response to commands.
A browser is used to send an HTTP command to a web server and establish a TCP connection (Transmission Control Protocol). The web server then sends HTML pages back to the user's browser these are what we would refer to as webpages. For example, when you enter a URL in a web browser, this actually sends an HTTP command to the web server, instructing it to fetch and transmit the requested webpage.
HTTP can also be used to transfer files from a web server to a web browser (or to any other requesting application that uses HTTP). It is referred to as a stateless protocol as each command is independent of another. The connection established between the browser and the web server is closed as soon as the web server responds to the initial command. In contrast, FTP is a two-way file transfer protocol. Once a connection is established between a workstation and a file server, files can be transferred back and fourth between the two entities.
For further information on HTTP based file transfer solutions, please visit the HTTP File Transfer section of the Pro2col website.