In my experience, I've used JavaScript to dynamically update HTML content by manipulating the DOM. For instance, I worked on a project where we needed to create a dynamic user interface that responded to user interactions. I used JavaScript to listen for events like button clicks and then updated the content of specific HTML elements accordingly. One example was a form where users could add multiple entries. When a user clicked the "Add" button, a new input field would appear on the page. This was achieved by creating new DOM elements using JavaScript and appending them to the existing HTML structure. This approach allowed us to provide a seamless and interactive experience for users.