Definition

• HTTP stands for hypertext transfer protocol, a computer language and set of rules that allows computers to share data in the World Wide Web. When you open your Internet browser and type in a URL (for instance, www.eHow.com), the browser on your computer (the "client") sends an HTTP request to the external computer (the "web server") for information. The web server receives and verifies the request and then transmits a web page back to your browser for you to view.
  
  

Protocol

• A protocol is an agreed-upon or standardized set of rules governing the transmission of information between electronic devices (in the case of HTTP, a client and web server). With HTTP, the protocol defines the structure of the data request and several methods by which you can access a resource (a web page, for instance).
  
  

Versions

• The initial version (1.0) of HTTP was a stateless system--the connection between the client (your computer) and the server lasted for a single, once-off request for a web page. As of 2010, version 1.1 allows you to download multiple resources with a single connection.
  
  In HTTPS requests, the "s" stands for "secure," meaning that data you enter--such as passwords, credit card and tax information--is encrypted when it is sent to the web server.