This example demonstrates the simplest possible integration of JavaScript within an HTML page: a plain script tag that logs a message to the console. The HTML document contains only a static text element, “Hello HTML,” while the linked external script, `index.js`, executes `console.log('Hello JavaScript!')` upon page load. The example uses no external libraries or rendering APIs, relying solely on the browser’s native JavaScript engine and the Document Object Model’s script element to bridge markup and code. It serves as a minimal building block for more complex visualization projects, highlighting the foundational setup required before adding any data or graphical libraries.