# Getting started with HTML

# Hello World

# Introduction

HTML (opens new window) (Hypertext Markup Language) uses a markup system composed of elements which represent specific content. Markup means that with HTML you declare what is presented to a viewer, not how it is presented. Visual representations are defined by Cascading Style Sheets (CSS) (opens new window) and realized by browsers. Still existing elements that allow for such (opens new window), like e.g. font (opens new window), "are entirely obsolete, and must not be used by authors"^[1].

HTML is sometimes called a programming language but it has no logic, so is a markup language. HTML tags provide semantic meaning and machine-readability to the content in the page.

An element usually consists of an opening tag (<element_name>), a closing tag (</element_name>), which contain the element's name surrounded by angle brackets, and the content in between: <element_name>...content...</element_name>

There are some HTML elements that don't have a closing tag or any contents. These are called void elements (opens new window). Void elements include <img>, <meta>, <link> and <input>.

Element names can be thought of as descriptive keywords for the content they contain, such as video, audio, table, footer.

A HTML page may consist of potentially hundreds of elements which are then read by a web browser, interpreted and rendered into human readable or audible content on the screen.

For this document it is important to note the difference between elements and tags:

Elements: video, audio, table, footer

Tags: <video>, <audio>, <table>, <footer>, </html>, </body>

# Element insight

Let's break down a tag...

The <p> tag represents a common paragraph.

Elements commonly have an opening tag and a closing tag. The opening tag contains the element's name in angle brackets (<p>). The closing tag is identical to the opening tag with the addition of a forward slash (/) between the opening bracket and the element's name (</p>).

Content can then go between these two tags: <p>This is a simple paragraph.</p>.

# Creating a simple page

The following HTML example creates a simple "Hello World" (opens new window) web page.

HTML files can be created using any text editor (opens new window). The files must be saved with a .html or .htm^[2] extension in order to be recognized as HTML files.

Once created, this file can be opened in any web browser.

<!DOCTYPE html>
<html lang="en">

    <head>
        <meta charset="UTF-8">
        <title>Hello!</title>
    </head>

    <body>
        <h1>Hello World!</h1>
        <p>This is a simple paragraph.</p>
    </body>

</html>

# Simple page break down

These are the tags used in the example:

Tag	Meaning
`<!DOCTYPE>`	Defines the HTML version used in the document. In this case it is HTML5. See the doctypes topic (opens new window) for more information.
`<html>`	Opens the page. No markup should come after the closing tag (`</html>`). The `lang` attribute declares the primary language of the page using the ISO language codes (opens new window) (`en` for English). See the Content Language topic (opens new window) for more information.
`<head>`	Opens the head section, which does not appear in the main browser window but mainly contains information about the HTML document, called metadata. It can also contain imports from external stylesheets and scripts. The closing tag is `</head>`.
`<meta>`	Gives the browser some metadata about the document. The `charset` attribute declares the character encoding (opens new window). Modern HTML documents should always use UTF-8 (opens new window), even though it is not a requirement. In HTML, the `<meta>` tag does not require a closing tag. See the Meta topic (opens new window) for more information.
`<title>`	The title of the page. Text written between this opening and the closing tag (`</title>`) will be displayed on the tab of the page or in the title bar of the browser.
`<body>`	Opens the part of the document displayed to users, i.e. all the visible or audible content of a page. No content should be added after the closing tag `</body>`.
`<h1>`	A level 1 heading for the page. See headings (opens new window) for more information.
`<p>`	Represents a common paragraph of text.

↑ HTML5, 11.2 Non-conforming features (opens new window)
↑ .htm is inherited from the legacy DOS (opens new window) three character file extension limit.

# Remarks

HTML (opens new window) (Hypertext Markup Language) is an XML (opens new window)-compliant system of annotating documents with 'tags'. It is used specifically to create content for web pages and web applications, which can then be shared over a network.

Apart from text, the current version of HTML supports many different types of media (opens new window), including images and videos.

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