LESS is a dynamic stylesheet language that extends the capabilities of CSS (Cascading Style Sheets). It allows developers to use variables, nested rules, and functions, making it easier to manage and maintain styles for web applications. By simplifying the process of writing CSS, LESS helps streamline the development workflow. LESS files are typically saved with a .less extension and are compiled into standard CSS files that browsers can read. This compilation process can be done using various tools or build systems, enabling developers to take advantage of features like mixins and operations for more efficient styling.