Note: Parts of this tutorial assume you know HTML. If you do not, consider reading this tutorial on HTML first. This tutorial is lengthy but very thorough.

1. The first place you can define a script is within the head of the HTML document. Scripts here aren't automatically executed when the page loads but can be referred to by other scripts within the document.
2. The next place you can define a script is within the body of the HTML document. Scripts here are executed as the page loads.
3. The last place you can define a script is within an event handler. You will learn more about these later.

When defining scripts in the head and body of HTML documents you are required to use a script tag, while if you are defining a script within an event handler, this tag is not required.

You can include the src attribute to the script tag if you would like to save your script to an external file and include it in the HTML file. Remember to use the .js extension when saving Javascript to an external file.
     <script src="menu.js">
The above would include the Javascript from the menu.js file.

Defining a Script (continued)