The HTML <script> tag is used to insert a JavaScript into an HTML page.
How to Put a JavaScript Into an HTML Page
<html>
<body>
<script type="text/javascript">
document.write("Hello World!");
</script>
</body>
</html>
The code above will produce this output on an HTML page:
Hello World!
To insert a JavaScript into an HTML page, we use the <script> tag. Inside the <script> tag we use the type attribute to define the scripting language.
So, the <script type="text/javascript"> and </script> tells where the JavaScript starts and ends:
<html>
<body>
<script type="text/javascript">
...
</script>
</body>
</html>
The word document.write is a standard JavaScript command for writing output to a page.
By entring the document.write command between the <script> and </script> tags, the browser will recognize it as a JavaScript command and execute the code line. In this case the browser will write Hello World! to the page:
<html>
<body>
<script type="text/javascript">
document.write("Hello World!");
</script>
</body>
</html>
HTML Comments to Handle Simple Browsers
Browsers that do not support JavaScript will display JavaScript as page content.
To prevent them from doing this, and as a part of the JavaScript standard, the HTML comment tag can be used to "hide" the JavaScript. Just add an HTML comment tag <!-- before the first JavaScript statement, and a --> (end of comment) after the last JavaScript statement.
<html>
<body>
<script type="text/javascript">
<!--
document.write("Hello World!");
//-->
</script>
</body>
</html>
The two forward slashes at the end of comment line (//) is the JavaScript comment symbol. This prevents JavaScript from executing the --> tag.
