JavaScript is a scripting language originally designed to run in a web browser and add logic to static HTML pages. Fundamentally, HTML is a declarative language for building sharable documents over the Internet and is not meant to perform operations such as mathematical calculations, data retrieval, and dynamic content generation. However, these functionalities can be achieved through the integration of JavaScript. For example, the HTML code below presents a webpage consisting of a simple calculator that adds two numbers entered by the user. The HTML code contains only a few elements including a heading (<h2>) to display the title of the page, two <input> controls to accept the user input, a <button> control to trigger the calculation, and a paragraph (<p>) to display the results. The <input> controls are assigned identifiers num1 and num2, and the paragraph contains the identifier result.</input></p></button></input></h2>