JavaScript can be written inside both the <head> section and <body> section. Sometimes we need to write the JavaScript code in both sections to better understand or calling the different functions.
While writing JavaScript code <head> and <body> sections we have to use <script> tag for both.
Here you can see an example where I have written JavaScript code in two ways by putting it inside the <head> section and by putting inside the <body> section. These two are the formal ways to write scripting code.
I always put it in the body section of the HTML document because It will help to load the page faster.
HTML / JS Code
<html> <head> <script type="text/javascript"> function book(){ alert ("JavaScript is Awesome"); } </script> </head> <body> <script type="text/javascript"> document.write("Leave it!! No need to develop."); </script> <input type="button" onClick="book()" value="DEVELOP"> </body> </html>