Introduction to Web Browsers

Web Browsers have come a long way from the days of the first internet web browser, Mosaic and the like. The monopoly of the Microsoft-authored Internet Explorer has been decisively broken and terminated possibly, forever. Web browsers today have progressed from being a mere internet-exploring tool to being a multi-purpose, multi-pronged application that brings several advantages to the web visitor. A web browser is defined as a software application, a typical HTTP client that helps the internet visitor to interpret the HTML documents and display the content from web servers or in file systems.Today there are a variety of internet browsers available. The prominent browsers available for personal computers include Microsoft Internet Explorer, Mozilla Firefox Opera Netscape and so on. A browser is the most commonly used kind of user agent. The largest networked collection of linked documents is known as the World Wide Web.

Web browsers communicate with web servers primarily using HTTP (hyper-text transfer protocol) to fetch webpages. HTTP allows web browsers to submit information to web servers as well as fetch web pages from them. The most commonly used HTTP is HTTP/1.1. Web Pages are located by means of a URL (uniform resource locator), which is treated as an address, beginning with http: for HTTP access. Many browsers also support a variety of other URL types and their corresponding protocols, such as ftp: for FTP (file transfer protocol), gopher: for Gopher, and https: for HTTPS (an SSL encrypted version of HTTP).

The generally accepted file format for a web page is usually HTML (hyper-text markup language) and is identified in the HTTP protocol using a MIME content type. Most browsers certainly support other technology formats in addition to HTML, such as the JPEG PNG and GIF image formats, and can be extended to support more through the use of plugins. The combination of HTTP content type and URL protocol specification allows web page designers to embed images, animations, video, sound, and streaming media into a web page, or to make them accessible through the web page.

In the beginning web browsers supported only a very simple version of HTML. The rapid development of web browsers led to the development of HTML into a more complex avatars. Modern web browsers support standards-based HTML and XHTML which should display in the same way across all browsers. Web sites today are designed using WYSIWYG HTML generation programs such as Macromedia Dreamweaver or Microsoft Frontpage. There are continuous development activities in developing standards, specifically with XHTML and CSS (cascading style sheets, used for page layout). Some of the more popular browsers include additional components to support Usenet news, IRC (Internet relay chat), and e-mail. Protocols supported may include NNTP (network news transfer protocol), SMTP (simple mail transfer protocol), IMAP (Internet message access protocol), and POP (post office protocol).

Different browsers have uniqueness built in because of the very features that they provide and very functions that they support. Modern browsers and web pages tend to utilize many features and techniques that did not exist in the early days of the web. The following is a list of some of the most notable features:

- HTTP and HTTPS
- HTML, XMLand XHTML
- GIF, PNGJPEG and SVG
- Cascading Style Sheets
- JavaScript
- Digital certificates
- RSS    
- Bookmarks 
- Caching
- Plugins like Macromedia Flash and Quick Time.

Other features generally include:
- Autocomplete
- Tabbed browsing
- Spatial navigation
- Caret navigation
- Screen reader
- Pop-up Blocker
- Ad filtering
- Phishing

Web Browsers have today established themselves as a most user-friendly and essential technology tool for surfing the internet. Web browsers help the visitors to the ethereal world of the web to view contents from different file formats, interact with other websites, incorporate appropriate technology to view/download/upload multi-media content and streaming multi-media. Web browsers today provide functionalities like blocking of unwanted pop-up advertisements, spywares and phishing attempts. They provide the convenience of tabbed browsing and come with advanced features like auto-fill and password and download managers.

Web browsers of today are not mere messengers between client and server. They are full-fledged programs capable of using fuzzy logic to select most appropriate content and help the web visitor to browse safely and pleasurably.