'LESS' is a versatile CSS preprocessor that enriches standard CSS with advanced features while maintaining backward compatibility. Conceived by Alexis Sellier in 2009, LESS integrates dynamic functionalities like variables, mixins, operations, and functions into CSS, significantly enhancing its manageability and scalability.

LESS empowers developers to write CSS that is both cleaner and more streamlined, promoting reusability. It introduces variables that store values for repeated use across stylesheets, streamlining the process of making widespread changes. Mixins in LESS facilitate the inclusion of one class's properties into another, akin to functions in conventional programming languages.

Furthermore, LESS enhances CSS with nesting capabilities, simplifying the handling of complex CSS structures. This nesting ability leads to a more structured and readable CSS coding style. LESS also provides support for operations and functions, allowing for more dynamic manipulation of CSS properties and values.

Before a webpage is loaded, LESS code is compiled into standard CSS. This compilation can be performed either client-side in the browser or server-side, with the latter typically being more efficient in production environments.

In summary, LESS extends the functionality and flexibility of CSS, making it an invaluable tool for web developers who seek to optimize their styling workflows. Its ability to enhance CSS with dynamic capabilities, while retaining compatibility with regular CSS, makes it particularly suited for intricate, large-scale web development endeavors.