Project Management

More Web administration basics

In the final installment of his three-part series, Mike Jackman examines more basic terminology that every Web administrator must know.

If you haven’t had time to stay current with the latest Web trends or if your Web skills have decayed, you’re in luck.

Previously, I wrote two articles to fill in any knowledge gaps. The first article defined basic Web terms that IT professionals should know. The second article listed four fundamental concepts every Web administrator should understand. In this third installment of the three-part series, I’ll provide explanations of additional common Web terms.

HTML
HTML, or Hypertext Markup Language, is the basic markup language of Web pages. Designers are so familiar with it now that they forget that it created exciting interaction with users. Although its features seem elementary now, built in to hypertext was the link, which is the most important development in the recent history of document storage and retrieval. Links are interactive and dynamic because they fetch different content based on user selections (or clicks).

HTML contains two important tags: <DIV> and <SPAN>. HTML also includes three important tag attributes: style, class, and ID. These tags and attributes are used with scripts and with cascading style sheets. On the simplest level, the attributes allow the designer to change the way a tag is displayed. For example, if you defined a style called .subtitle that had a bold, large, green, sans-serif font, adding a class attribute could change the way almost any tag displayed text.

Another user interaction feature built in to HTML are form tags. In HTML, tags are used to format styles in a Web document. Tags are contained within angle brackets (< or >), such as <p> (paragraph) and <h1> (heading 1). Most tags need an end tag to show the browser where to stop applying a style. End tags contain a slash, as in </p> or </h1>. The text between the tags is subsequently displayed in the specified style when a Web page is rendered.

IFRAMES
IFRAMES, or inline frames, is a type of frame or Web page division that is only supported in Internet Explorer (3.0 and above). These scrolling frames can be set up much like images. In other words, they can be placed anywhere in an HTML document. They use an <iframe> tag.

Because users can scroll the information contained in the IFRAMES, they are interactive, in a sense. If scripts are used to change the information within the frames, then they become dynamic.

iHTML
IHTML, or Inline Hyptertext Markup Language, is a server-side scripting language that allows designers to create dynamic, interactive Web pages. Unlike PHP and other server-side scripting languages, it’s not free. For more information, see the Internet Applications Company Web site.

Java and JavaScript
Java (not to be confused with JavaScript) is a full-fledged programming language developed by Sun Microsystems. Java code, which resembles C++, is stored in an intermediate form, called byte-code, rather than the usual compiled binary code of executable files. The byte-code helps the language serve multiple platforms.

Java code is run through an interpreter. Java can be made into applications or applets, a program that can be run by a Web browser. Java is used in many types of advanced dynamic Web applications, from e-commerce to publishing. You can learn more about Java here.

JavaScript, however, is a scripting language based on the syntax of C. It’s not Java, which is a full-fledged programming language.

Instead, JavaScript is an interpreted language, meaning that it is run on-the-fly inside a Web browser. Because it is platform-independent, it is also portable, which makes it ideal for creating dynamic, interactive pages (although there are headaches due to browser differences).

An example of an interactive use for JavaScript is the popular mouseover, where images change when users pass the mouse over a link. Other uses for JavaScript include cascading menus, applications such as shopping carts, form verification, currency converters, games, and loan or mortgage calculators. Incidentally, Microsoft’s implementation of JavaScript is called JScript.

Layers
Layers involve using a Netscape-only method of creating dynamic Web pages using the <layer> tag. Further, <layer> tags are only a Netscape 4.0 solution. Netscape 6.0 doesn’t support layers. The best advice is not to use <layer> tags.

Perl
Perl, or Practical Extraction and Report Language, is a scripting language that is used for CGI scripts. Perl is but one of the languages used for CGI, and its syntax is similar to C. Perl scripts are often confused with CGI (when it’s really just one type of CGI script) because the file extension is often .cgi.

Perl scripts can be used to create discussion boards, manipulate forms, or perform many kinds of interactive, dynamic Web work. For more information, see the O’Reilly Perl Web site. Like many of the tools defined in this glossary, Perl is free.

PHP
PHP (PHP: Hypertext Preprocessor) is a server-side scripting language for creating dynamically generated Web pages, just like Perl. It’s often used to manipulate content from a database. Unlike Perl, though, you embed PHP commands directly into HTML Web pages.

Note that PHP must be enabled on the Web server. The syntax of the language is similar to C, Java, and Perl. Files use a .php extension. PHP tags start with <?php followed by commands separated by a semicolon (;).

For more information on PHP, see the PHP Web site. Did I mention it’s free?

SQL and MySQL
SQL, or structured query language, provides a way to set up relational databases and access data in database applications such as Oracle, Microsoft Access, MySQL, and Microsoft SQL Server.

MySQL is a small, efficient, relational database (a database that can link information in separate data files). It’s free, open source, and supports standard SQL syntax. Since databases are used in all kinds of e-commerce and online publishing schemes, why not use one that’s well documented, efficient for Web sites regardless of size, and free? For more information, see the MySQL Web site.

SSI
SSI, or server-side include, is a method for adding content to a Web page. When the server sees the special include tag, it dynamically adds the indicated information to the Web page before sending the information to the user’s browser.

There are many uses for SSI. One of the most popular is for adding information that will be repeated on many pages, for example, a copyright notice or a navigation bar. By using SSI, Web pages can be shorter because designers can keep the source of the repeating information in a separate file.

By making one change to a navigation bar file, for example, all the pages that use it are automatically updated, saving the author considerable manual work.

Depending on how the server is configured, Web files using SSI may end in .shtml or even .asp. Used in conjunction with a server-side script, the information in the SSI can even change. Includes can also execute programs and display information in variables, such as the current date and time.

VBScript
VBScript is based on the Visual Basic language. VBScript is syntactically identical to Visual Basic.

Check out TechProGuild’s Daily Drill Down to learn more about how VBScript and JavaScript can be combined.

XML
XML, or eXtensible Markup Language, is the buzzword as far as Web pages are concerned. This is especially true in the area of online commerce. XML is a tagged language, like HTML. However, it has rules that make the use of tags more consistent, and it lets designers define their own tags. Because of the way XML works, content can be completely separated from presentation, taking CSS a step further. In fact, XML pages can be bound to style sheets and HTML pages.

Using XML extends the abilities of browsers to display information beyond what can be used with HTML. For instance, XML can be used to display types of documents for which HTML doesn’t have tags, such as a book with mathematical formulas. It can also be manipulated like a database. XML tags can be structured as records and fields, and the XML file can be used to look up and display specific data. XML tags can also structure a document, such as a manual, by sections, thus making it possible to work with each of those sections in different ways.

By using XML with HTML, CSS, databases, and scripting, XML offers a powerful way to create dynamic and interactive Web pages. For more information, order TechRepublic’s guide to XML. Another useful resource is the O’Reilly XML Web site.

Conclusion
There are many ways to support the writing of dynamic and interactive Web pages. I hope that this series on Web terms and concepts will help you better understand the different methods that are used.
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