Template Engines: Jade and Handlebars
A template engine is a library or a framework that uses some rules/languages to interpret data and render views. In the case of web applications, views are HTML pages (or parts of them), but they can be JSON or XML files, or, in desktop programs, GUIs. For those of you familiar with the model–view–controller concept, templates belong to the view.
In web apps, it’s beneficial to use templates because we can generate an infinite number of pages dynamically with a single template! Another side benefit is when we need to change something; we can do it in one place only.
If we go back to the diagrams ...