Pug, formerly known as Jade, is a high-performance templating engine for Node.js. It is designed to simplify the process of writing HTML by providing a clean, readable syntax that leverages indentation and reduces boilerplate code. Pug allows developers to create dynamic, reusable HTML templates with ease, supporting features like variables, loops, conditionals, and mixins for modular code. Its ability to generate HTML dynamically makes it a powerful tool for server-side rendering in web applications. Pug integrates seamlessly with various web frameworks, such as Express, enhancing productivity and maintainability. By offering a more concise and structured way to write HTML, Pug improves the efficiency of front-end development and contributes to cleaner, more maintainable codebases.