Update README.md with doctrine related information

README.md

@@ -11,6 +11,20 @@ in the Symfony world and the bundle is maintained by developers in the Doctrine
 IMPORTANT: This bundle is developed for Symfony 2.1 and up. For Symfony 2.0 applications the DoctrineBundle
 is still shipped with the core Symfony repository.
 
+## What is Doctrine?
+
+The Doctrine Project is the home of a selected set of PHP libraries primarily focused on providing persistence
+services and related functionality. Its prize projects are a Object Relational Mapper and the Database Abstraction
+Layer it is built on top of. You can read more about the projects below or view a list of all projects.
+
+Object relational mapper (ORM) for PHP that sits on top of a powerful database abstraction layer (DBAL).
+One of its key features is the option to write database queries in a proprietary object oriented SQL dialect
+called Doctrine Query Language (DQL), inspired by Hibernates HQL. This provides developers with a powerful
+alternative to SQL that maintains flexibility without requiring unnecessary code duplication.
+
+DBAL is a powerful database abstraction layer with many features for database schema introspection,
+schema management and PDO abstraction.
+
 ## Installation
 
 ### 1. Old deps and bin/vendors way