The document is a presentation by Deepak Rai from Mindfire Solutions discussing the PHP Reflection API, which allows programs to inspect and modify their own structure at runtime. It covers the usage of the API through command line examples, various classes such as ReflectionClass, ReflectionMethod, and their respective methods, as well as practical applications like generating HTML forms and database tables. Additionally, it highlights the benefits of using the Reflection API in PHP frameworks and for documentation generation.