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Web Accessing content through the Web consists of communication between a Web browser client and a Web server utilizing HTTP (Hyper Text transfer Protocol) (Fig. 1)
Fig.1 Web Overview
The following is a step by step description of the communication path, as shown above. It assumes that the Web server, the primary domain naming system (DNS) server, and the client computer are connected to the Internet and that all communication is conducted through the Internet. Step 1 and 2 – The end-user types a URL into the Web browser. The client computer finds the Internet protocol (IP) number associated with the domain name in the URL from DNS server. Step 3 and 4 – The client computer uses the IP number obtained from the primary DNS server to request through HTTP (Hyper Text transfer Protocol), the default HTML (Hyper Text Markup Language) file from the Web server associated with the URL. The Web server sends the default HTML file to the client computer. The default HTML file provides information to the client computer for requesting all associated files-such as graphics-for the Web site’s complete homepage.
When the client computer and Web browser request and receive files from the same URL, the client computer is not required to perform a DNS lookup as described in Step 1 and 2. When the client computer attempts to retrieve a Web site from a different URL, the client computer must then perform Step 1 and 2 again.
Web Hosting
The complex web of servers consists of computer systems installed with Web-server software and connected to the Internet. These servers can be found in any facility with Internet connectivity. The process of maintaining and operating one of these servers is called Web Hosting. Web Hosting can be conducted in-house by the owner of the web site, or it can be outsourced to a Web Hosting Company.
Web Hosting Companies are typically companies with one or more data-center facilities that are connected to the Internet. Web hosting provided by Web Presence providers can vary widely with respect to service quality and cost. Some providers consist simply of a room in the basement of a house and a tier-1 (T1) line connected to the local ISP (Internet Service Provider). Others, however, are corporations with state-of-the-art hosting centers consisting of power sources, a dry pipe-fire suppression system, and an experienced operations group, available 24 hours a day, seven days a week.
Web hosting can be provided on a shared computer environment or on a dedicated computer system. When a Web site consists only of standard HTML (Hyper text markup language) code and receives a small number of visitors, shared hosting service is the best solution. When a Web site consists of complex common gateway interface (CGI) scripts and proprietary programs and receives a large number of visitors, dedicated hosting service is the best solution.
Web Hosting Implementation on a Dedicated Platform
The basic concept of Web hosting on a dedicated computer system consists of hosting one Web site on one computer system. The dedicated environment offers complete flexibility and security to both the Web Presence provider and the customer.
Web hosting on a dedicated computer system is the simplest and most straightforward method of operating a Web site. Because the computer system contains only one Web site, the configuration of software is standardized, as outlined in the software-installation documentation. Furthermore, system resources are dedicated to only one Web site and, therefore, are not constrained by any other process not associated with the operations of that site.
Web Hosting Implementation on a Shared Platform
The basic concept of Web hosting on a shared computer environment consists of hosting many different Web sites on one computer system. The shared environment offers economic benefits to both the Web Presence provider and the customer. Because the Web-hosting environment is the same for all customers, the provider gains economic benefits from allocating portions of the total cost of the hardware, software, maintenance and operation, and customer support amongst all customers. Therefore, the total fixed cost is less on a per-customer basis than with dedicated hosting. The customer gains economic benefit by the reduced price of the Web-hosting service.
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