Connecting to Resources Using a Web Browser
A web browser is an application that lets users display and interact with information locate on the World Wide Web or a local intranet. A web page can contain hyperlinks to other pages on the same or different website. Web browsers allow a user to access information from many websites by traversing these links. Web browsers format HTML information for display, so the appearance of a web page can differ between browsers. Although browsers are normally used to access the World Wide Web, they can also be used to access information on intranet web servers content in file systems.
Web browsers available for personal computers include Internet Explorer, Mozilla Firefox, Safari, Netscape and Opera in descending order of popularity. At the time of writing (February 2007) Internet Explorer dominated almost 80% of the browser market, followed by Firefox on nearly 15%.
Web browsers communicate with web servers via HTTP (HyperText Transfer Protocol) which allows web browsers to submit information to web servers and as fetch web pages from them. Pages are located by means of a URL (Uniform Resource Locator), an address beginning with http: for HTTP access. Many browsers also support other URL types and their corresponding protocols, eg: ftp: for FTP (File Transfer Protocol) and https: for HTTPS (a secure version of HTTP).
Web pages are normally written in HTML, but most browsers support a variety of other formats such as the JPEG, PNG and GIF image formats. Browsers can be extended to support additional media types by means of plugins. Early web browsers only supported a very simple version of HTML, but this was rapidly expanded, often by the use of non-standard dialects of HTML, leading to problems with interoperability.
Modern web browsers support a combination of standard and non-standard HTML and XHTML, which should display in the same way across all browsers. No current browser fully supports HTML 4.01, XHTML 1.x or CSS 2.1. Many sites are developed using WYSIWYG HTML generation programs such as Macromedia Dreamweaver or Microsoft FrontPage which generate non-standard HTML. This hinders the development of standards, particularly with XHTML Xtended HTML) and CSS (Cascading Style Sheets), which is used for page layout.
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A record of the actions you have taken to connect to resources using a web browser can contribute towards your logbook for this unit. |
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