Page 26 - DCAP202_Fundamentals of Web Programming

Unit 2: HTML Introduction

2.2 Web Server Notes

A Web server is a program that, using the client/server model and the World Wide Web’s
Hypertext Transfer Protocol ( HTTP ), serves the files that form Web pages to Web users (whose
computers contain HTTP clients that forward their requests). Every computer on the Internet
that contains a Web site must have a Web server program. Two leading Web servers are Apache,
the most widely-installed Web server, and Microsoft’s Internet Information Server ( IIS ). Other
Web servers include Novell’s Web Server for users of its NetWare operating system and IBM’s
family of Lotus Domino servers, primarily for IBM’s OS/390 and AS/400 customers.
Web servers often come as part of a larger package of Internet- and intranet-related programs
for serving e-mail, downloading requests for File Transfer Protocol (FTP) files, and building
and publishing Web pages. Considerations in choosing a Web server include how well it works
with the operating system and other servers, its ability to handle server-side programming,
security characteristics, and publishing, search engine, and site building tools that may come
with it.

Self Assessment

Fill in the blanks:
6. A ........................... is a program that, using the client/server model and the World Wide
Web’s Hypertext Transfer Protocol ( HTTP ), serves the files that form Web pages to Web
users.
7. Every computer on the Internet that contains a ........................... must have a Web server
program.

2.3 Web Browser

Short for Web browser, a software application used to locate, retrieve and also display content on
the World Wide Web, including Web pages, images, video and other files. As a client/server
model, the browser is the client run on a computer that contacts the Web server and requests
information. The Web server sends the information back to the Web browser which displays the
results on the computer or other Internet-enabled device that supports a browser.
Today’s browsers are fully-functional software suites that can interpret and display HTML Web
pages, applications, JavaScript, AJAX and other content hosted on Web servers. Many browsers
offer plug-ins which extend the capabilities of a browser so it can display multimedia information
(including sound and video), or the browser can be used to perform tasks such as
videoconferencing, to design web pages or add anti-phishing filters and other security features
to the browser.

2.3.1 Definition

A web browser is a software application for retrieving, presenting and traversing information
resources on the World Wide Web. An information resource is identified by a Uniform Resource
Identifier (URI) and may be a web page, image, video or other piece of content. Hyperlinks
present in resources enable users easily to navigate their browsers to related resources. A web
browser can also be defined as an application software or program designed to enable users to
access, retrieve and view documents and other resources on the Internet.

LOVELY PROFESSIONAL UNIVERSITY 19