Home rental and relocation services system

2.2.7 Client/Server architecture

A network architecture in which each computer or process on the network is either a Client or a Server. Servers are powerful computers or processes dedicated to managing disk drives (file servers), printers (print servers), or network traffic (network servers ). Clients are PCs or workstations on which users run applications. Clients rely on servers for resources, such as files, devices, and even processing power.

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Figure 2: Client /Server architecture Source: www.webbasedprogramming.com

2.2.8 Tools, techniques and languages used developing software 2.2.8.1 JavaScript

A scripting language developed by Netscape to enable Web authors to design interactive sites. Although it shares many of the features and structures of the full Java language, it was developed independently. JavaScript can interact with HTML source code, enabling Web authors to spice up their sites with dynamic content. JavaScript is endorsed by a number of software companies and is an open language that anyone can use without purchasing a license. It is supported by recent browsers from Netscape and Microsoft, though Internet Explorer supports only a subset, which Microsoft calls Jscript

2.2.8.2 Apache

Apache is generally recognized as the world's most popular Web server (HTTP server). Originally designed for UNIX servers, Apache has been ported to Windows and other Network Operating Systems (NOS). The name "Apache" derives from the word "patchy" that the Apache developers used to describe early versions of their software.

Apache provides a full range of Web server features, including CGI, SSL, and virtual domains. Apache also supports plug-in modules for extensibility. Apache is reliable, free, and relatively easy to configure.

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The Apache HTTP server is free software distributed by the Apache Software Foundation. The Apache Software Foundation promotes various free and open source advanced Web technologies.

2.2.8.3 PHP

PHP is an open source server side programming language extensively used for web scripts and to process data passed via the Common Gateway Interface from HTML forms etc. PHP can be written as scripts that reside on the server and may produce HTML output that downloads to the web browser. Alternatively, PHP can be embedded within HTML pages that are then saved with a .php file extension.

In an HTML document, PHP script (similar syntax to that of Perl or C) is enclosed within special PHP tags. Because PHP is embedded within tags, the author can jump between HTML and PHP (similar to ASP and Cold Fusion) instead of having to rely on heavy amounts of code to output HTML. And, because PHP is executed on the Server, the client cannot view the PHP code.

PHP can perform any task that any CGI program can do, but its strength lies in its compatibility with many types of database. Also, PHP can talk across networks using IMAP, SNMP, NNTP, POP3, or HTTP.

2.2.8.4 HTML

Hyper Text Markup Language, the coding language used to create hypertext documents for the World Wide Web. In HTML, a block of text can be surrounded with tags that indicate how it should appear (for example, in bold face or italics). Also, in HTML a word, a block of text, or an image can be linked to another file on the Web. HTML files are viewed with a World Wide Web browser.