HTML

Introduction

What is HTML?

HTML stands for Hyper Text Markup Language
HTML is the standard markup language for creating Web pages
HTML describes the structure of a Web page
HTML consists of a series of elements
HTML elements tell the browser how to display the content
HTML elements label pieces of content such as "this is a heading", "this is a paragraph", "this is a link", etc.

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 that this document is an HTML5 document.
The <html> element is the root element of an HTML page
The <head> element contains meta information about the HTML page.
The <title> element specifies a title for the HTML page (which is shown in the browser's title bar or in the page's tab).
The <body> element defines the document's body, and is a container for all the visible contents, such as headings, paragraphs, images, hyperlinks, tables, lists, etc.
The <h1> element defines a large heading.
The <p> element defines a paragraph.

What is an HTML Element?

An HTML element is defined by a start tag, some content, and an end tag:

<tagname> Content goes here... </tagname>

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

<h1> My First Heading. </h1>

<p> My first paragraph. </p>

Start tag	Element content	End tag
<h1>	My First Heading	</h1>
<p>	My first paragraph.	</p>
<br>	none	none

Note: Some HTML elements have no content (like the <br> element). These elements are called empty elements. Empty elements do not have an end tag!

Web Browsers

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

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

HTML History

Since the early days of the World Wide Web, there have been many versions of HTML:

Year	Version
1989	Tim Berners-Lee invented www
1991	Tim Berners-Lee invented HTML
1993	Dave Raggett drafted HTML+
1995	HTML Working Group defined HTML 2.0
1997	W3C Recommendation: HTML 3.2
1999	W3C Recommendation: HTML 4.01
2000	W3C Recommendation: XHTML 1.0
2008	WHATWG HTML5 First Public Draft
2012	WHATWG HTML5 Living Standard
2014	W3C Recommendation: HTML5
2016	W3C Candidate Recommendation: HTML 5.1
2017	W3C Recommendation: HTML5.1 2nd Edition
2017	W3C Recommendation: HTML5.2

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>

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 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 < > 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>

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

How to View HTML Source?

Have you ever seen a Web page and wondered "Hey! How did they do that?"

View HTML Source Code:

Right-click in an HTML page and select "View Page Source" (in Chrome) or "View Source" (in Edge), or similar in other browsers. This will open a window containing the HTML source code of the page

Inspect an HTML Element:

Right-click on an element (or a blank area), and choose "Inspect" or "Inspect Element" to see what elements are made up of (you will see both the HTML and the CSS). You can also edit the HTML or CSS on-the-fly in the Elements or Styles panel that opens.

Reference

All the documentation in this page is taken from W3C