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\HTML Introduction

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:
<html>
<head>
<title>Page title</title>
</head>
<body>
<h1>This is a heading</h1>
<p>This is a paragraph.</p>
<p>This is another paragraph.</p>
</body>
</html>
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.
Follow the four steps below to create your first web page with Notepad or TextEdit.

Step 1: Open Notepad (PC)

Windows 8 or later:
Open the Start Screen (the window symbol at the bottom left on your screen). Type Notepad.
Windows 7 or earlier:
Open Start > Programs > Accessories > Notepad

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 "Ignore rich text commands in HTML files".
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>

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

View in 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:

HTML Basic Examples

Don't worry if these examples use tags you have not learned.
You will learn about them in the next chapters.

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.
You will learn more about attributes in a later chapter.

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).

Nested HTML Elements

HTML elements can be nested (elements can contain elements).
All HTML documents consist of nested HTML elements.
This example contains four HTML elements:

Example

<!DOCTYPE html>
<html>
<body>

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

</body>
</html>

Example Explained

The <html> element defines the whole document.
It has a start tag <html> and an end tag </html>.
The element content is another HTML element (the <body> element).
<html>
<body>

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

</body>
</html>
The <body> element defines the document body.
It has a start tag <body> and an end tag </body>.
The element content is two other HTML elements (<h1> and <p>).
<body>

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

</body>
The <h1> element defines a heading.
It has a start tag <h1> and an end tag </h1>.
The element content is: My First Heading.
<h1>My First Heading</h1>
The <p> element defines a paragraph.
It has a start tag <p> and an end tag </p>.
The element content is: My first paragraph.
<p>My first paragraph.</p>


Do Not Forget the End Tag

Some HTML elements will display correctly, even if you forget the end tag:

Example

<html>
<body>

<p>This is a paragraph
<p>This is a paragraph

</body>
</html>
The example above works in all browsers, because the closing tag is considered optional.
Never rely on this. It might produce unexpected results and/or errors if you forget the end tag.

Empty HTML Elements

HTML elements with no content are called empty elements.
<br> is an empty element without a closing tag (the <br> tag defines a line break).
Empty elements can be "closed" in the opening tag like this: <br />.
HTML5 does not require empty elements to be closed. But if you want stricter validation, or if you need to make your document readable by XML parsers, you must close all HTML elements properly.

Use Lowercase Tags

HTML tags are not case sensitive: <P> means the same as <p>.
The HTML5 standard does not require lowercase tags, but W3C recommends lowercase in HTML, and demandslowercase for stricter document types like XHTML.




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