The <head> tag in HTML is used to define the head section of a document, which contains meta-information about the document, such as the title, character set, linked stylesheets, scripts, and more. Here are some common elements that you can include within the <head> tag along with examples:

Title Tag: The <title> tag is used to define the title of the HTML document. It appears on the browser tab or window.

html
<!DOCTYPE html>
<html>
<head>
    <title>My Web Page</title>
</head>
<body>
    <!-- Content goes here -->
</body>
</html>

Meta Tags: Meta tags provide metadata about the HTML document, such as the character set, viewport settings, and keywords for search engines.

html
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="keywords" content="HTML, CSS, JavaScript">
</head>
<body>
    <!-- Content goes here -->
</body>
</html>

Link Tag (for CSS): The <link> tag is used to link an external stylesheet to the HTML document.

html
<!DOCTYPE html>
<html>
<head>
    <link rel="stylesheet" type="text/css" href="styles.css">
</head>
<body>
    <!-- Content goes here -->
</body>
</html>

Script Tag (for JavaScript): The <script> tag is used to include JavaScript code within the HTML document, either inline or by referencing an external script file.
```
html
<!DOCTYPE html>
<html>
<head>
    <script src="script.js"></script>
</head>
<body>
    
</body>
</html>
```

Base Tag: The <base> tag specifies a base URL/target for all relative URLs in a document.

html
<!DOCTYPE html>
<html>
<head>
    <base href="https://example.com/">
</head>
<body>
    <!-- Content goes here -->
</body>
</html>

These are some of the common elements that you can use within the <head> tag to enhance and provide additional information about your HTML document. Remember that the <head> section doesn't contain content visible to the user; it's more about document structure and metadata.