What are HTML tags?
- HTML tags are used to mark-up HTML elements
- HTML tags are surrounded by the two characters < and >
- The surrounding characters are called angle brackets
- HTML tags normally come in pairs like <b> and </b>
- The first tag in a pair is the start tag, the second tag is the end tag
- The text between the start and end tags is the element content
- HTML tags are not case sensitive, <b> means the same as <B>
Logical vs. Physical Tags
In HTML there are both logical
tags and physical tags. Logical tags are designed to describe (to the browser)
the enclosed text's meaning. An example of a logical tag is the <strong>
</strong> tag. By placing text in between these tags you are telling the
browser that the text has some greater importance. By default all browsers make
the text appear bold when in between the <strong> and </strong> tags.
Physical tags on the other hand
provide specific instructions on how to display the text they enclose. Examples
of physical tags include:
- <b>: Makes the text bold.
- <big>: Makes the text usually one size bigger than what's around it.
- <i>: Makes text italic.
Physical tags were invented to
add style to HTML pages because style sheets were not around, though the
original intention of HTML was to not have physical tags. Rather than use
physical tags to style your HTML pages, you should use style sheets.
HTML Elements
Remember
the HTML example from the previous page:
<html>
<head>
<title>My First
Webpage</title>
</head>
<body>
This is my first homepage.
<b>This text is bold</b>
</body>
</html>
This
is an HTML element:
<b>This text is bold</b>
The
HTML element begins with a start tag: <b>
The
content of the HTML element is: This text is bold
The
HTML element ends with an end tag: </b>
The
purpose of the <b> tag is to define an HTML element that should be
displayed as bold.
This
is also an HTML element:
<body>
This is my first homepage.
<b>This text is bold</b>
</body>
This HTML element starts with the
start tag <body>, and ends with the end tag </body>. The purpose of
the <body> tag is to define the HTML element that contains the body of
the HTML document.
Nested Tags
You may have noticed in the
example above, the <body> tag also contains other tags, like the <b>
tab. When you enclose an element in with multiple tags, the last tag opened
should be the first tag closed. For example:
<p><b><em>This
is NOT the proper way to close nested tags.</p></em></b>
<p><b><em>This
is the proper way to close nested tags. </em></b></p>
Note:
It doesn't
matter which tag is first, but they must be closed in the proper order.
Why Use Lowercase Tags?
You may notice we've used
lowercase tags even though I said that HTML tags are not case sensitive. <B>
means the same as <b>. The World Wide Web Consortium (W3C), the group
responsible for developing web standards, recommends lowercase tags in their
HTML 4 recommendation, and XHTML (the next generation HTML) requires lowercase
tags.
Tag Attributes
Tags can have attributes. Attributes
can provide additional information about the HTML elements on your page. The <tag>
tells the browser to do something, while the attribute tells the browser how to
do it. For instance, if we add the bgcolor attribute, we can tell the browser
that the background color of your page should be blue, like this: <body
bgcolor="blue">.
This tag defines an HTML table: <table>.
With an added border attribute, you can tell the browser that the table should
have no borders: <table border="0">. Attributes always come in
name/value pairs like this: name="value". Attributes are always added
to the start tag of an HTML element and the value is surrounded by quotes.
Quote Styles, "red" or 'red'?
Attribute values should always be
enclosed in quotes. Double style quotes are the most common, but single style
quotes are also allowed. In some rare situations, like when the attribute value
itself contains quotes, it is necessary to use single quotes:
name='George
"machine Gun" Kelly'
Note:
Some tags we
will discuss are deprecated, meaning the World Wide Web Consortium (W3C) the
governing body that sets HTML, XML, CSS, and other technical standards decided
those tags and attributes are marked for deletion in future versions of HTML
and XHTML. Browsers should continue to support deprecated tags and attributes,
but eventually these tags are likely to become obsolete and so future support
cannot be guaranteed.
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