The JavaScript engine is only one of several tools browsers use to deliver a user interface that is both dynamic and able to asynchronously interact with multiple databases and events. Other main components include WebAPIs (including the DOM), two queues, and the Event Loop.
Sometimes, we need to display the same basic HTML, but with some customized data interspersed here and there. The Handlebars.js library is perfect for this. It takes less than 5 minutes to learn how to use this simple and efficient templating tool.