What is HTTP?

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HTTP, an acronym that stands for HyperText Transfer Protocol, is the code that Internet browsers use to find and transmit website information, including words, pictures, audio files and any other type of data. Specifically, the HTTP code sends messages to the Web servers that house individual website data. The web servers use a program – an HTTP daemon – that waits for requests from browsers and other servers and handles them appropriately.

The connection between the browser and the Web server is only maintained during the communication process. When the two are done communicating, the connection is broken and is only re-established when the browser sends a message saying it is ready to visit another website. While the term HTTP was coined by Ted Nelson in the 1960s, the HTTP code wasn't widely used until the early 1990s. HTTP/0.9 was the first version, introduced in 1991.  The current version being widely used is HTTP/1.1, which was released on 1997.

HTTP Codes

When the Web browser sends out codes requesting data, the Web server has the option of sending more than 100 different codes back in response. Among the most common are:

200 OK: This is the standard response for a successful HTTP request.

301 Moved Permanently: This response is sent when the Web server wants the browser to know that all future requests should be directed to a new URL.

401 Unauthorized: This is the response sent when authentication is needed to access the desired site. Often, it will cause the browser to ask for a username and password.

403 Forbidden: This is the response sent when a browser is not allowed access to a website. Unlike with a 401 response, no opportunity to input a username or password is given.

404 Not Found: This is the response when the Web server cannot find the URL the browser is attempting to access. This code is often given when a URL is mistyped.

500 Internal Server Error: A generic error message for when a Web server faces some form of internal problem, such as when it is overloaded or when there is a script or configuration error.

503 Service Unavailable: This is the response when a Web server is temporarily unavailable due to being overloaded or undergoing maintenance.

What is HTTPS?

In addition to the HTTP code, websites that pride themselves on having top-notch security use the HTTPS code, which stands for HyperText Transfer Protocol with Secure Sockets Layer. The HTTPS code is used to transfer encrypted data over the Web. The HTTPS code is used by any website that allows for e-commerce transactions. Those include major online retailers, as well as banking and credit card websites. Internet users can tell when the site they are visiting is using a secure connection by looking at the address bar to see if the website starts with "https://" Web sites use the security code as a way to help prevent eavesdropping and man-in-the-middle attacks.