Twig is a flexible and lightweight template engine for PHP, designed to make it easier to create and manage HTML templates. It allows developers to separate the presentation layer from the business logic, promoting cleaner and more maintainable code. Twig uses a simple syntax that resembles regular HTML, making it accessible for both beginners and experienced developers. One of Twig's key features is its ability to extend functionality through custom filters and functions. It also supports template inheritance, enabling developers to create a base template that can be reused across multiple pages. This makes it a popular choice for web applications built with frameworks like Symfony and Laravel.