HTML Elements
HTML elements are the fundamentals of HTML. HTML documents are simply a text file made up of HTML elements. These elements are defined using HTML tags.
An HTML element is an individual component of an HTML document. Any given web page consists of many HTML elements.
HTML tags tell your browser which elements to present and how to present them. Where the element appears is determined by the order in which the tags appear.
HTML consists of over 100 tags. Don't let that put you off though - you will probably find that most of the time, you only use a handful of tags on your web pages. Having said that, I highly recommend learning all HTML tags eventually - but we'll get to that later.
OK, lets look more closely at the example that we created in the previous lesson.
Explanation of the above code:
- The
!DOCTYPE...
declaration tells the browser which version of HTML the document is using. - The
html
element is the document's root element - it can be thought of as a container that all other tags sit inside (except for the !DOCTYPE declaration). - The
head
tag contains information that is not normally viewable within your browser (such as meta tags, JavaScript and CSS), although thetitle
tag is an exception to this. The content of thetitle
tag is displayed in the browser's title bar (right at the very top of the browser). - The
body
tag is the main area for your content. This is where most of your code (and viewable elements) will go. - The
h1
tag defines a level 1 heading. - The
p
tag defines a paragraph. This contains the body text.
Closing your Tags
As mentioned in a previous lesson, you'll notice that all of these HTML elements have opening and closing tags, and that the content of the element is placed in between them. There are a few exceptions to this rule.
You'll also notice that the closing tag is slightly different to the opening tag — the closing tag contains a forward slash (/
) after the <
. This tells the browser that this tag closes the previous one.
Indents and Carriage Returns
You can indent the code and add extra carriage returns if you like. This can help with readability, and it doesn't affect the way the page is displayed in the browser.
In fact, code indenting is a universal practice in computer programming circles, and most HTML editors automatically indent the code for you as you type.
For example, we could take the above example, and indent it like the following example, and it will still appear the same in the browser.
UPPERCASE or lowercase?
You can use uppercase or lowercase when coding HTML, however, most developers use lowercase. This helps the readability of your code, and it also saves you from constantly switching between upper and lower case. Lowercase also helps keep your code XML compliant (if you're using XHTML), but but that's another topic.
Therefore...
- Good:
head
- OK:
HEAD
Optional Tags
Some of the above tags are optional in certain situations. In particular, the html
, head
, and body
tags can all be omitted.
So it would be perfectly valid to change the above example to this:
However, there are some very specific rules around when you can and can't do this. For example, the html
start tag can be omitted if it's not immediately followed by a comment, and the same applies to its end tag. And the head
element's start tag can only be omitted if the element is empty, or if the first thing inside the element is an element. And its end tag can only be omitted if the element is not immediately followed by a space character or a comment. The body element also has its own specific rules for omitting tags.
If you're interested in learning which tags you can leave out, check the HTML specification for the rules around the specific tags you'd like to omit.
If you're not sure whether or not it's OK to omit a tag, just include all tags (like in the first example).
In the next lesson, we learn about some of the more common formatting tags.