Web Browser

A web browser is an application used for retrieving, presenting, and transferring information over the Internet. Information is gathered by a Uniform Resource Identifier (URI), which can be a web page, an image, a video, or any other type of content viewed on the browser. The most widely used web browsers are Google Chrome, Mozilla Firefox, Microsoft Internet Explorer, and Apple Safari.

The first web browser was invented by Sir Tim Berners-Lee in 1990 called the Worldwide Web, later known as Nexus. In 1993 Marc Andreessen innovated browser software by releasing Mosaic, later known as Netscape, released in 1994 and was the world’s first popular browser.

In 1995, Microsoft released Internet Explorer, which was bundled with windows, and by 2002 Explorer had 95 percent of browser usage. In 1996 Opera joined the browser market but never gained popularity. Opera-mini has been widely used in mobile devices, being preinstalled on over 40 million phones, and also in Nintendo’s Wii game consoles.

In 1998, Netscape started the Mozilla Foundation attempting to produce a competitive browser with open source software, in 2004 it became what is known today as Firefox. In August 2011, Firefox had 28 percent of the browser market. Apple Safari was released in January 2003 and by 2011 it had a 7 percent share of the browser market.

In 2008 Chrome entered the market and has increasingly gained popularity, while explorer’s popularity has decreased. By August 2011, Chrome usage was at 16 percent, and by December 2011, it surpassed Explorer 8 as the most used browser.

The function and use of a web browser is for a user to input a Uniform Resource Locator (URL) into the browser, usually beginning with a Hypertext Transfer Protocol (HTTP). Once the browser locates the resource, the associated content is passed through the browser’s layout engine and rendered into a document. Then it is displayed on the web page as an image, text, audio, or video file, and sometimes contains a plug-in to support Flash and Java applications. If a file is unsupported, the user is prompted to save the file to a disk. Some content may contain hyperlinks, when clicked it will redirect to another URI and display the information upon the web page.

The features within web browsers range from a text-based interface to interfaces that allow a wide variety of formats which can include e-mail support, and live chat. All major browsers have the ability to allow the user to open multiple resources at the same time, either by opening a different browser window or clicking on another tab in the same window.

Most browsers include a pop-up blocker to prevent unwanted windows appearing without the user’s consent. Users can also bookmark pages frequently visited into a list so the user can quickly access the web page. In Internet Explorer this feature is called favorites. Most web browsers can also have downloadable components called plug-ins that provide additional features.

The user interface of most web browsers contains these elements:

· Back and forward buttons to access the previous or next page that was viewed.

· A refresh button to reload the current page.

· A stop button to cancel the current page being loaded.

· A home button to return to the user’s home page.

· An address bar to enter the URL of the desired resource.

· A search bar to input information to provide a list of web pages relating to the information wanted.

· A status bar that displays the loading progress of the resource.

· Displays the link when cursor is hovering over the hyperlink.

· Page zooming capabilities.

· Allows user to quickly delete cache, cookies, and browsing history.

· Browser extensions, which extend the functionality of the web browser.