# About the documentation > {material-regular}`format_quote;2em` > > The Grand Unified Theory of Documentation > >
-David Laing
There is a secret that needs to be understood in order to write good software documentation: there isn't one thing called *documentation*, there are four. They are: *tutorials*, *how-to guides*, *technical reference* and *explanation*. They represent four different purposes or functions, and require four different approaches to their creation. Understanding the implications of this will help improve most documentation - often immensely. [More information on this topic.](https://documentation.divio.com)