Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)

If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.

If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||^$document". Then just click OK.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide

NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The Book is Here... and Now On Sale!

Enjoy The TCP/IP Guide? Get the complete PDF!
The TCP/IP Guide

Custom Search

Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  TCP/IP Key Applications and Application Protocols
           9  TCP/IP File and Message Transfer Applications and Protocols (FTP, TFTP, Electronic Mail, USENET, HTTP/WWW, Gopher)
                9  TCP/IP World Wide Web (WWW, "The Web") and the Hypertext Transfer Protocol (HTTP)
                     9  TCP/IP World Wide Web and Hypertext Overview and Concepts

Previous Topic/Section
World Wide Web System Concepts and Components
Previous Page
Pages in Current Topic/Section
Next Page
World Wide Web Addressing: HTTP Uniform Resource Locators (URLs)
Next Topic/Section

World Wide Web Media and the Hypertext Markup Language (HTML)
(Page 3 of 4)

Common HTML Elements

Table 273 provides a brief description of some of the more common elements used in the body of an HTML message and the tags that define them, to give you a feel for how the language works:

Table 273: Common Hypertext Markup Language (HTML) Elements


Example Element and Tags



<p>Jack and Jill went
up the hill to fetch a
pail of water…</p>

Delineates a paragraph of text. Note that everything between the start and end tags will be considered one paragraph, even if split onto multiple lines as I have done here; line breaks are not significant in HTML formatting, only tags.

Line Break

George W. Bush<br>
The White House<br>
1600 Pennsylvania Ave., NW<br>
Washington, DC 20500

Forces a line break. Used instead of the paragraph tag to present lines close together, such as addresses.


<h1>First Topic</h1>

Defines section headings, to allow information in a long document to be displayed in hierarchical form. Six sets of tags are defined, from <h1> and </h1> to <h6> and </h6>. Browsers will automatically display the “higher-level” headings in more prominent ways, by using larger fonts, underlining the text, or similar.


<p>Shopping list:

Allows information to be presented as a list. The tag “<ul>” means “unnumbered list” and causes the list items to be shown usually as bullet points. Alternately, “<ol>” (“ordered list”) can be used to show the items preceded by 1, 2, 3 and so on.

Horizontal Rule

…end of this part of the story.</p>
<hr size= “3”>
<p>Start of next part of story…

Draws a horizontal line across the page; the “size” parameter controls its thickness. Used to separate logical sections in a document.


<img src=”companylogo.gif” alt=”XYZ Industries Logo” align=“center”>

Displays an inline image in the appropriate section of the text. The “src” parameter is a relative or absolute URL for the image, and numerous other parameters can be included to define the image's alignment, size, “alternate text” to display if the browser is non-graphical (as shown here with the “alt” parameter) and much more.


<a href=&t_.htm“”>Click here to visit The PC Guide</a>

Hyperlinks to another document. The “a” in the tag stands for “anchor”, which is the formal name for a hyperlink. the “href” parameter specifies the URL of the link.

Most browsers will underline or otherwise highlight the text between the start and end tags to make it clear that the text represents a hyperlink. It is also possible to give a hyperlink to an image by combining the “<img>” and “<a>” tags.


<a name=“Step4”>Step 4: Remove paint using scrubbing tool.</a>

Creates a bookmark that can be used to hyperlink to a particular section in a document. For example, if the bookmark in this example was in a document at URL “”, the URL “” refers to this particular place in the document. See the next topic on URLs for more details.


<td>1st row, 1st column.</td>
<td>1st row, 2nd column.</td>
<td>2nd row, 1st column.</td>
<td>2nd row, 2nd column.</td>

Displays information in tabular form. Each “<tr>” and “</tr>” tag set defines one row of the table; within each row, each “<td>” and “</td>” pair defines one table data element. Many different parameters can be provided for each of these tags to control table size and appearance.


<form method="POST" action="">
<input type="hidden" name="PRODUCT" value="widget">
<input type=”text” name=”QUANTITY” size="3">
<input type="submit" value="Click Here to Proceed to the Secure Processing Site">

Defines an HTML form, allowing various sorts of information to be submitted by a client to a program on a Web site designed to process forms. The form consists of the initial “<form>” tag that describes what action to be taken when the submission button is pressed, and other form items such as predefined variables, text entry fields, and buttons; one example of each of these items is shown here.


<script language=javascript>
(Javascript code)


Allows instructions in a scripting language to be included in an HTML document. Most often used for Javascript.

Previous Topic/Section
World Wide Web System Concepts and Components
Previous Page
Pages in Current Topic/Section
Next Page
World Wide Web Addressing: HTTP Uniform Resource Locators (URLs)
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $

Home - Table Of Contents - Contact Us

The TCP/IP Guide (
Version 3.0 - Version Date: September 20, 2005

Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.