HTML (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) and realized by browsers. Still existing elements that allow for such, like e.g.
font, "are entirely obsolete, and must not be used by authors".
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:
There are some HTML elements that don't have a closing tag or any contents. These are called void elements. Void elements include
Element names can be thought of as descriptive keywords for the content they contain, such as
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:
Let's break down a tag...
<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 (
Content can then go between these two tags:
<p>This is a simple paragraph.</p>.
The following HTML example creates a simple "Hello World" web page.
HTML files can be created using any text editor. The files must be saved with a
.htm 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>
These are the tags used in the example:
|Defines the HTML version used in the document. In this case it is HTML5.|
See the doctypes topic for more information.
|Opens the page. No markup should come after the closing tag (|
See the Content Language topic for more information.
|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 |
|Gives the browser some metadata about the document. The |
See the Meta topic for more information.
|The title of the page. Text written between this opening and the closing tag (|
|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 |
|A level 1 heading for the page.|
See headings for more information.
|Represents a common paragraph of text.|