You maybe become confused learning Javascript. The simple command in this tutorial is How to insert javascript into html page. The first learning is make message "Hello World". The simple concept code is bellow :
<html>
<body>
<script type="text/javascript">
......
</script>
</body>
</html>
And the example is bellow :
<html>
<body>
<script type="text/javascript">
document.write("Hello World!")
</script>
</body>
</html>
After insert that code you will get message Hello World! after you open your html page.
Note: If we had not entered the <script> tag, the browser would have treated the document.write("Hello World!") command as pure text, and just write the entire line on the page.
<html>
<body>
<script type="text/javascript">
......
</script>
</body>
</html>
And the example is bellow :
<html>
<body>
<script type="text/javascript">
document.write("Hello World!")
</script>
</body>
</html>
After insert that code you will get message Hello World! after you open your html page.
Note: If we had not entered the <script> tag, the browser would have treated the document.write("Hello World!") command as pure text, and just write the entire line on the page.