Similar functionality on multiple pages

1. How to use JavaScript in multiple pages?
2. Which tag is used to include multiple HTML pages in single page?

How to use JavaScript in multiple pages?

You can store one or more of your JavaScript scripts in a single . js file and access them from multiple HTML pages. Put the script in an external JavaScript file. If you have the script already inside your HTML page, remove all the JavaScript code inside the <script> tag and paste it into a separate file.

Which tag is used to include multiple HTML pages in single page?

You could use iframes in HTML. And page1. html would be your base page.