What is a LESS file?
A LESS file is a style sheet used for webpages and created with the Leaner Style Sheets (LESS). It implements additions to the standard CSS language, that makes it easy to learn and implement. A LESS file extends the CSS by adding features such as Variables, Mixins, Nesting, Operations, Functions, Namespaces and Accessors.
Leaner Style Sheets File Format
LESS files are created in the format of CSS, extending its capabilities by the additional features that it offers. These are saved as text files and can be opened in LESS style sheet language, CodeKit, and Adobe Dreamweaver.