A template engine is a software component that helps generate dynamic web pages by combining templates with data. It allows developers to create HTML structures that can be filled with variable content, making it easier to manage and update web applications. Commonly used in web development, template engines streamline the process of rendering views by separating the presentation layer from the business logic. Popular template engines include Mustache, Handlebars, and Thymeleaf. These tools use placeholders within templates, which are replaced with actual data when the page is rendered. This approach enhances code reusability and maintainability, allowing developers to focus on functionality while ensuring a consistent look and feel across their applications.