By Russell Shaw
Many different components are involved in getting a Web page up and running. A Web browser, server and host work together to call up a given site while firewalls protect internal networks from intrusion.
What a Web Browser Does
A Web browser is a computer software program that can go to a Web server and request a page. Internet Explorer and Netscape Navigator are the most common browsers, although there are a number of others. Online services such as America Online (AOL) and CompuServe use adaptations of these popular browsers. The browser then pulls the page through the Internet, and ultimately shows it on your computer screen. It’s also able to interpret the various computer “languages” that Web sites use to form Web pages, and it displays the Web site you’ve requested on your computer screen.
What a Web Server Does
Web servers are programs that run on server machines, either at your business or at the Web host. They identify and retrieve the particular page you’ve requested through your browser, and then instruct that it be sent out over the Internet and displayed on the requesting computer screen. They handle many requests on many pages simultaneously. In general, the more powerful the server machine, the more pages it can serve at the same time.
What a Web Host Does
Web hosts literally house Web sites and provide the Web services that make those sites available on the Internet. Host computers store the contents of your site, as well as your e-mail and Web site address identifying information that enables others to communicate with your site. Some larger companies and many government and educational institutions host their own sites, but virtually all individual users and many companies find it too unwieldy and expensive to purchase and maintain the equipment necessary to host their own sites.
What a Domain Name Does
Web browsers and Web servers work together through Web hosts to call up Web pages by using the Internet protocol (IP) address that is registered along with a domain name. A Web browser finds a Web page based on its IP address, also known as its URL (uniform resource locator). All Web servers on the Internet also have domain names, which are registered to a particular IP address. Domain names are easier for humans to remember than the numerical locator that makes up the actual IP address. Ours is “www.trimariner.com” (the entire URL for our site is “http://www.trimariner.com”). This name is actually a three part designation: the host name (“www,” for World Wide Web), the domain name (“trimariner”), and the top-level domain name, “.com,” which indicates a commercial or business site. Other domains include “.edu,” for education-oriented sites; “.org,” for organizations; “.net,” for some specialized Internet and computing sites; “.gov,” for government sites; and “.mil” for military sites. Domain name servers at network access points are able to access a list of all currently valid registered domain names that are registered and match them to their corresponding numerical IP address.
What a Firewall Does
A firewall is a security system on a computer network that blocks unauthorized packets from using the Internet to gain access to the company LAN (Local Area Network). The firewall protects the LAN resources from users outside the network with the help of a proxy server. Proxy servers are software that sit within a firewall and monitor access to the Internet. For instance, when someone on a company network attempts to log on to an outside Web site, her request is sent from her machine to a proxy server, which then contacts the Web server and retrieves the site. The indirect connection that the proxy server enables reinforces the firewall. Many companies use proxy servers to monitor Web use by their employees. A firewall is often installed in a specially designated computer separate from the rest of the network so that no incoming request can get directly at private network resources. This barrier protects internal company data, as well as Web pages, from being corrupted by outsiders.
The above article was first made available at Workz. com.