The .w3-tag is used to add additional information to the content. For example, some website highlights some sections to be new or when they have updated a section they add updated tag with that division so that user can see that they have updated to added new divisions on their site. This class when used creates a rectangular tag which acts as a label or sign on the site. Its default color is black.
Example: Adding tags in the HTML page.
HTML
<!DOCTYPE html>
<html>
<head>
<!-- Adding W3.CSS file through external link -->
<link rel="stylesheet" href=
"https://www.w3schools.com/w3css/4/w3.css">
</head>
<body>
<!-- w3-container is used to add
16px padding to any HTML element. -->
<!-- w3-center is used to set the content
of the element to the center. -->
<div class="w3-container w3-center">
<!-- w3-text-green sets the text
color to green. -->
<!-- w3-xxlarge sets font size to 32px. -->
<h2 class="w3-text-green w3-xxlarge">
Welcome To GFG
</h2>
</div>
<!-- Tags in W3.CSS -->
<div class="w3-container">
<h5>Updates
<!-- Adding Tag with value "More later" -->
<span class="w3-tag">More Later</span>
</h5>
<h5>Messages
<!-- Adding Tag with value "New" -->
<span class="w3-tag">New</span>
</h5>
<h5>Request
<!-- Adding Tag with value "Done" -->
<span class="w3-tag">Done</span>
</h5>
</div>
</body>
</html>
Output:

Colors can be added to the tags using the color classes of W3.CSS.
Example: Adding colored tags on the HTML Page.
HTML
<!DOCTYPE html>
<html>
<head>
<!-- Adding W3.CSS file through external link -->
<link rel="stylesheet" href=
"https://www.w3schools.com/w3css/4/w3.css">
</head>
<body>
<!-- w3-container is used to add
16px padding to any HTML element. -->
<!-- w3-center is used to set the content
of the element to the center. -->
<div class="w3-container w3-center">
<!-- w3-text-green sets the text color
to green. -->
<!-- w3-xxlarge sets font size to 32px. -->
<h2 class="w3-text-green w3-xxlarge">
Welcome To GFG
</h2>
</div>
<!-- Tags in W3.CSS -->
<div class="w3-container">
<h5>Updates
<!-- Adding Tag with value "More later" -->
<span class="w3-tag w3-teal">More Later</span>
</h5>
<h5>Messages
<!-- Adding Tag with value "New" -->
<span class="w3-tag w3-blue">New</span>
</h5>
<h5>Request
<!-- Adding Tag with value "Done" -->
<span class="w3-tag w3-purple">Done</span>
</h5>
</div>
</body>
</html>
Output:

We can add various sized tags using font-sizes available in W3.CSS classes.
Example: Adding tags of different sizes.
HTML
<!DOCTYPE html>
<html>
<head>
<!-- Adding W3.CSS file through external link -->
<link rel="stylesheet" href=
"https://www.w3schools.com/w3css/4/w3.css">
</head>
<body>
<!-- w3-container is used to add
16px padding to any HTML element. -->
<!-- w3-center is used to set the
content of the element to the center. -->
<div class="w3-container w3-center">
<!-- w3-text-green sets the text color
to green. -->
<!-- w3-xxlarge sets font size to 32px. -->
<h2 class="w3-text-green w3-xxlarge">
Welcome To GFG
</h2>
</div>
<!-- Tags in W3.CSS -->
<div class="w3-container">
<h5>Updates
<!-- Adding Tag with value "More later" -->
<span class="w3-tag w3-teal w3-small">
More Later</span>
</h5>
<h5>Messages
<!-- Adding Tag with value "New" -->
<span class="w3-tag w3-blue
w3-large">New</span>
</h5>
<h5>Request
<!-- Adding Tag with value "Done" -->
<span class="w3-tag w3-purple
w3-jumbo">Done</span>
</h5>
</div>
</body>
</html>
Output:

We can also add round-edged tags using border-radius classes in W3.CSS.
Example:
HTML
<!DOCTYPE html>
<html>
<head>
<!-- Adding W3.CSS file through external link -->
<link rel="stylesheet" href=
"https://www.w3schools.com/w3css/4/w3.css">
</head>
<body>
<!-- w3-container is used to add
16px padding to any HTML element. -->
<!-- w3-center is used to set the content of
the element to the center. -->
<div class="w3-container w3-center">
<!-- w3-text-green sets the text color
to green. -->
<!-- w3-xxlarge sets font size to 32px. -->
<h2 class="w3-text-green w3-xxlarge">
Welcome To GFG
</h2>
</div>
<!-- Tags in W3.CSS -->
<div class="w3-container">
<h5>Updates
<!-- Adding Tag with value "More later" -->
<span class="w3-tag w3-teal
w3-round">More Later</span>
</h5>
<h5>Messages
<!-- Adding Tag with value "New" -->
<span class="w3-tag w3-blue
w3-round-large">New</span>
</h5>
<h5>Request
<!-- Adding Tag with value "Done" -->
<span class="w3-tag w3-purple
w3-round-xlarge">Done</span>
</h5>
</div>
</body>
</html>
Output: