What is HTML?

HTML is the standard markup language for creating Web pages.

  • HTML stands for Hyper Text Markup Language
  • HTML describes the structure of Web pages using markup
  • HTML elements are the building blocks of HTML pages
  • HTML elements are represented by tags
  • HTML tags label pieces of content such as “heading”, “paragraph”, “table”, and so on
  • Browsers do not display the HTML tags, but use them to render the content of the page

A Simple HTML Document

Example

<!DOCTYPE html>
<html>
<head>
<title>Page Title</title>
</head>
<body>

<h1>My First Heading</h1>
<p>My first paragraph.</p>

</body>
</html>

Example Explained

  • The <!DOCTYPE html> declaration defines this document to be HTML5
  • The <html> element is the root element of an HTML page
  • The <head> element contains meta information about the document
  • The <title> element specifies a title for the document
  • The <body> element contains the visible page content
  • The <h1> element defines a large heading
  • The <p> element defines a paragraph

HTML Tags

HTML tags are element names surrounded by angle brackets:

<tagname>content goes here…</tagname>

  • HTML tags normally come in pairs like <p> and </p>
  • The first tag in a pair is the start tag, the second tag is the end tag
  • The end tag is written like the start tag, but with a forward slash inserted before the tag name

Tip: The start tag is also called the opening tag, and the end tag the closing tag.

Web Browsers

The purpose of a web browser (Chrome, IE, Firefox, Safari) is to read HTML documents and display them.

The browser does not display the HTML tags, but uses them to determine how to display the document:

View in Browser


HTML Page Structure

Below is a visualization of an HTML page structure:

 

Note: Only the content inside the <body> section (the white area above) is displayed in a browser.


The <!DOCTYPE> Declaration

The <!DOCTYPE> declaration represents the document type, and helps browsers to display web pages correctly.

It must only appear once, at the top of the page (before any HTML tags).

The <!DOCTYPE> declaration is not case sensitive.

The <!DOCTYPE> declaration for HTML5 is:

<!DOCTYPE html>

HTML Versions

Since the early days of the web, there have been many versions of HTML:

Version Year
HTML 1991
HTML 2.0 1995
HTML 3.2 1997
HTML 4.01 1999
XHTML 2000
HTML5 2014

HTML Editors

Write HTML Using Notepad or TextEdit

Web pages can be created and modified by using professional HTML editors.

However, for learning HTML we recommend a simple text editor like Notepad (PC) or TextEdit (Mac).

We believe using a simple text editor is a good way to learn HTML.

Step 1: Open TextEdit (Mac)

Open Finder > Applications > TextEdit

Also change some preferences to get the application to save files correctly. In Preferences > Format > choose “Plain Text”

Then under “Open and Save”, check the box that says “Display HTML files as HTML code instead of formatted text”.

Then open a new document to place the code.

Step 2: Write Some HTML

Write or copy some HTML into Notepad.

<!DOCTYPE html>
<html>
<body><h1>My First Heading</h1>

<p>My first paragraph.</p>

</body>
</html>

Notepad

Step 3: Save the HTML Page

Save the file on your computer. Select File > Save as in the Notepad menu.

Name the file “index.htm” and set the encoding to UTF-8 (which is the preferred encoding for HTML files).

View in Browser

You can use either .htm or .html as file extension. There is no difference, it is up to you.

Step 4: View the HTML Page in Your Browser

Open the saved HTML file in your favorite browser (double click on the file, or right-click – and choose “Open with”).

The result will look much like this:

View in Browser

HTML Basic Examples

HTML Documents

All HTML documents must start with a document type declaration: <!DOCTYPE html>.

The HTML document itself begins with <html> and ends with </html>.

The visible part of the HTML document is between <body> and </body>.

Example

<!DOCTYPE html>
<html>
<body><h1>My First Heading</h1>
<p>My first paragraph.</p>

</body>
</html>

HTML Headings

HTML headings are defined with the <h1> to <h6> tags.

<h1> defines the most important heading. <h6> defines the least important heading:

Example

<h1>This is heading 1</h1>
<h2>This is heading 2</h2>
<h3>This is heading 3</h3>

HTML Paragraphs

HTML paragraphs are defined with the <p> tag:

Example

<p>This is a paragraph.</p>
<p>This is another paragraph.</p>

HTML Links

HTML links are defined with the <a> tag:

Example

<a href=”https://www.w3schools.com”>This is a link</a>

The link’s destination is specified in the href attribute.

Attributes are used to provide additional information about HTML elements.

HTML Images

HTML images are defined with the <img> tag.

The source file (src), alternative text (alt), width, and height are provided as attributes:

Example

<img src=”w3schools.jpg” alt=”W3Schools.com” width=”104″height=”142″>

HTML Buttons

HTML buttons are defined with the <button> tag:

Example

<button>Click me</button>

HTML Lists

HTML lists are defined with the <ul> (unordered/bullet list) or the <ol>(ordered/numbered list) tag, followed by <li> tags (list items):

Example

<ul>
<li>Coffee</li>
<li>Tea</li>
<li>Milk</li>
</ul>

HTML Elements

HTML Elements

An HTML element usually consists of a start tag and end tag, with the content inserted in between:

<tagname>Content goes here…</tagname>

The HTML element is everything from the start tag to the end tag:

<p>My first paragraph.</p>
Start tag Element content End tag
<h1> My First Heading </h1>
<p> My first paragraph. </p>
<br>

HTML elements with no content are called empty elements. Empty elements do not have an end tag, such as the <br> element (which indicates a line break).

HTML Attributes

Attributes provide additional information about HTML elements.

HTML Attributes

  • All HTML elements can have attributes
  • Attributes provide additional information about an element
  • Attributes are always specified in the start tag
  • Attributes usually come in name/value pairs like: name=”value”

The href Attribute

HTML links are defined with the <a> tag. The link address is specified in the hrefattribute:

Example

<a href=”https://www.w3schools.com”>This is a link</a>

You will learn more about links and the <a> tag later in this tutorial.

The src Attribute

HTML images are defined with the <img> tag.

The filename of the image source is specified in the src attribute:

Example

<img src=”img_girl.jpg”>

The width and height Attributes

Images in HTML have a set of size attributes, which specifies the width and height of the image:

Example

<img src=”img_girl.jpg” width=”500″ height=”600″>

The image size is specified in pixels: width=”500″ means 500 pixels wide.

You will learn more about images in our HTML Images chapter.

The alt Attribute

The alt attribute specifies an alternative text to be used, when an image cannot be displayed.

The value of the attribute can be read by screen readers. This way, someone “listening” to the webpage, e.g. a vision impaired person, can “hear” the element.

Example

<img src=”img_girl.jpg” alt=”Girl with a jacket”>

The alt attribute is also useful if the image does not exist:

Example

See what happens if we try to display an image that does not exist:

<img src=”img_typo.jpg” alt=”Girl with a jacket”>

The style Attribute

The style attribute is used to specify the styling of an element, like color, font, size etc.

Example

<p style=”color:red”>I am a paragraph</p>

The lang Attribute

The language of the document can be declared in the <html> tag.

The language is declared with the lang attribute.

Declaring a language is important for accessibility applications (screen readers) and search engines:

<!DOCTYPE html>
<html lang=”en-US”>
<body>…

</body>
</html>

The first two letters specify the language (en). If there is a dialect, use two more letters (US).

The title Attribute

Here, a title attribute is added to the <p> element. The value of the title attribute will be displayed as a tooltip when you mouse over the paragraph:

Example

<p title=”I’m a tooltip”>
This is a paragraph.
</p>

Chapter Summary

  • All HTML elements can have attributes
  • The title attribute provides additional “tool-tip” information
  • The href attribute provides address information for links
  • The width and height attributes provide size information for images
  • The alt attribute provides text for screen readers
  • At W3Schools we always use lowercase attribute names
  • At W3Schools we always quote attribute values with double quote

HTML Attributes

Below is an alphabetical list of some attributes often used in HTML, which you will learn more about in this tutorial:

Attribute Description
alt Specifies an alternative text for an image, when the image cannot be displayed
disabled Specifies that an input element should be disabled
href Specifies the URL (web address) for a link
id Specifies a unique id for an element
src Specifies the URL (web address) for an image
style Specifies an inline CSS style for an element
title Specifies extra information about an element (displayed as a tool tip)

A complete list of all attributes for each HTML element, is listed in our: HTML Attribute Reference.

HTML Headings