Internet/Web Definitions & Terminology

A lot of people think creating web pages is difficult because of all the computer concepts and terminology... but it's not so bad. Find a heavily caffeinated drink, maybe a candy bar or two, and read on.

HTML - Hypertext Markup Language

HTML is a collection of formatting commands that create the hypertext documents that are used as Web pages. When you point your Web browser to a URL, the browser interprets the HTML commands embedded in the page ir receives and uses them to format the page's text and graphic elements. HTML commands cover many types of text formatting (bold and italic text, lists, headline fonts in various sizes, and so on), and also have the ability to include graphics and other nontext elements.

Development and maintenance of HTML standards is coordinated by the World Wide Web Consortium.

The style aspect of HTML has become less important as the use of Cascading Style Sheets (CSS) has become more widely accepted.

XHTML - Extensible Hypertext Markup Language

XHTML is an acronym for "eXtensible HyperText Markup Language", a reformulation of HTML 4.0 as an XML 1.0 application. XHTML provides the framework for future extensions of HTML and has replaced HTML as the underlying language for Web pages.

XHTML tags are all lowercase and is a stricter, tidier version of HTML. All tags, including empty elements, must be closed, where with HTML 4 some did not. Otherwise, the elements (tags) and attributes are almost identical to HTML.

If you're familiar with HTML 4, XHTML will be easy to learn and use. XHTML 1.0 was released on January 26th as a Recommendation by the W3C.

CSS - Cascading Style Sheets

CSS (Cascading Style Sheets) is a formatting language, used to provide more customized web pages and make it easier for multiple pages to use the same styles. Browser support has been slower than would be ideal, but most recent versions of the popular browsers are finally supporting CSS acceptably.

Using CSS, you can define colours, backgrounds, borders, margins, alignment, fonts, sizes and loads of other things for almost any part of your web pages. The basic idea is to use CSS for all style/appearance aspects of a Web page while using XHTML/HTML for just the structure.

The word cascading refers to how styles are applied to an element in a Web page. If styles defined for one element oppose each other, the later one will be used, unless another one more specifically refers to the element. Cascading also means that each object inherits from its parent object or parent class.

One of the powerful advantages of using CSS is that you can place all your style information in one file, and then have each Web page refer back to that file, allowing you to make one change in the CSS file that will then affect every page of your site. This has obvious use if you maintain a site with hundereds of individual pages.

DHTML - Dynamic HTML

Dynamic HTML is really just HTML with a few new elements plus access to those elements via a scripting language (like JavaScript.) These elements give you more precise control over how your page looks and lets you manipulate those elements programmatically using scripts.

Originally, HTML was designed without much though given to layouts. You had little control over how your text and images were displayed on the page. This was in anticipation of pages being viewed on a variety of platforms and machines with different screen sizes and available system fonts.

Later, the <table> and <font> tags were added to allow a little more control over content layout and style. But these still had their limitations. JavaScript was introduced to allow for some manipulation of certain page elements, such as images and form inputs, through programming but was also somewhat limited. The idea was basically to allow for behavior on a page, and not just something that "sat there."

The Document Object Model (DOM) defines both the properties of various page elements and the methods used to change them. Using scripts, you can dynamically alter the content of your page. For example, changes can be made based on the particular browser being used or in response to a user action.

PHP - PHP: Hypertext Preprocessor

According to PHP.net (the official source of PHP) the name PHP is a recursive acronym for "PHP: Hypertext Preprocessor". It is a widely-used Open Source general-purpose scripting language that is especially suited for Web development and can be embedded into HTML.

What this means is that the source (code) is open (free) for anyone to use. Whereas other Scripting languages may have proprietary costs involved. PHP syntax draws upon the programming languages C, Java, and Perl allowing it to run on a variety of platforms and work with many different databases. The easy to learn source code is designed for web development and can be inserted directly into your html page. The Source is then executed on the server, rather than downloaded and executed by the browser.

MySQL - Structured Query Language

MySQL is the world's most popular open source (free) database, recognized for its speed and reliability. (Pronounced my-es-q-el.)

A database is a structured collection of data and can be anything from a picture gallery to a shopping list. MySQL's ingenious software architecture makes it extremely fast and easy to customize.

Commonly combined with PHP, MySQL allows you to create Web pages on demand based on choices made by a visitor to your site. Information is pulled from the database, and through PHP or another scripting language translated into HTML for a browser to display.

JavaScript

JavaScript is a Client-Side language, which means the code is sent through the Internet to the user's computer. All of the JavaScript commands run on the user's computer, not on the Server.

JavaScript is not intended to be a full featured programming language to compete with C++ or Java. While some advanced techniques may be supported, JavaScript was created as a tool to add interactivity to HTML pages.

An interpretted language is executed line-by-line by the computer that loads the page (see Client-Side above). The advantage to Interpreted languages is that the same code might be usable on a variety of machines (JavaScript will run in Netscape, IE, Mozilla, and Opera on a PC, Mac, Linux, or Unix computer). The down-side is that interpretted code runs slower as it has to be turned into instructions specific to the CPU and operating system on a line-by-line basis. A compiled program is already interpretted before it is downloaded - but generally must be recompiled for each CPU/OS combination.

Java

A high-level programming language developed by Sun Microsystems. Java was originally called OAK, and was designed for handheld devices and set-top boxes. Oak was unsuccessful so in 1995 Sun changed the name to Java and modified the language to take advantage of the burgeoning World Wide Web.

Java is an object-oriented language similar to C++, but simplified to eliminate language features that cause common programming errors. Compiled Java code can run on most computers because Java interpreters and runtime environments, known as Java Virtual Machines (VMs), exist for most operating systems, including UNIX, the Macintosh OS, and Windows.

Java is a general purpose programming language with a number of features that make the language well suited for use on the World Wide Web. Small Java applications are called Java applets and can be downloaded from a Web server and run on your computer by a Java-compatible Web browser.

The Difference Between the Internet and the Web

The World Wide Web is a network of computers each of which is running a program which can respond to requests from Web browsers. The benefits of computers in storing and disseminating information are magnified by the use of HTML and the Web. Now, individuals, businesses, and governments can share information quickly over computer networks by a method which is easy to access and read.

The Internet is the global collection of publicly accessible computer networks which are installed in schools, businesses, homes, and other locations. There are computer networks installed in similar facilities which are not publicly accessible. These networks are now being called Intranets because they have the potential to be utilized by their owners in similar fashion to the Internet. It may be said, therefore, that the Web is a subset of the Internet. The Internet offers methods of access beyond WWW such as file transfer (FTP) and "mainframe" hosting (Telnet).

cPanel

cPanel (short for "control panel") is software installed on a web server designed for end users and allows control over everything from adding and removing e-mail accounts to administering MySQL databases.

This admin system comes with all of the web hosting packages offered by the U.P. Web Maestro.

FTP - File Transfer Protocol

A set of computer rules used when transferring files over the Internet from one computer to another. (Software currently used by the U.P. Web Maestro for this purpose is called FileZilla.)

People often refer to "FTP'ing files" to or from a server. It's a way to retrieve or send files between your computer and a remote server.

There are many Internet sites that have set up public collections of material (software, text, etc.) available by logging in as "anonymous" and are thusly called "anonymous ftp servers". Many of these sites were active long before the World Wide Web was born.

IP Address

Every machine connected to the the Internet has a unique number assigned to it, called an IP address. Without this unique address, you would not be able to communicate with other computers. An IP address always consists of four numbers seperated by periods, with the numbers themselves being any of a range between 0 and 255. 198.175.10.38 is an example of what an IP address looks like.

To find out what your IP address is (if you're using Windows) go to your command or dos prompt, and type in ipconfig. This will return a few sets of numbers, if you look carefully, you will be able to find your IP address among them.

A dedicated IP address is set aside specifically for one domain, which was common in the early days of the Internet. This means that if someone types in the numeric form of the IP address the same domain will always appear in the browser as if you'd typed the domain name itself.

A shared IP address is an IP address that is used by many domains, and the server sorts out the requests made by browsers based on the domain name sent to the server by typing or clicking on a link.

Because shared IP's are sharing server resources, it is cheaper to host your site with a shared IP. Usually much cheaper. The downside is that you're sharing server resources. Depending on the server, there can be a noticeable decrease in performance, especially when Internet traffic to your server is high. With a dedicated IP address you are basically reserving more resources for your site.

Blacklist

A popular spam-filtering method that attempts to stop unwanted email by blocking messages from a preset list of senders. Blacklists are records of email addresses or IP addresses that have been previously used to send spam. When an incoming message arrives, the spam filter checks to see if its IP or email address is on the blacklist to see if it is considered spam and should be rejected.

The problem with blacklists is that they can also misidentify legitimate senders as spammers. These so-called false positives can result if a spammer happens to be sending junk mail from an IP address that is also used by legitimate email users. (This has the potential to happen in all shared hosting environments.) Also, since many clever spammers routinely switch IP addresses and email addresses to cover their tracks, a blacklist is always slightly lagging behind the newest sources of spam.