Doctrine offers PHP libraries that help developers manage database storage and object mapping, primarily through its Object Relational Mapper (ORM) and Database Abstraction Layer (DBAL). These tools simplify database interactions by allowing developers to map objects in their code to database tables, making them essential for backend development in frameworks like Symfony and Laravel. Unlike its competitors, Doctrine operates as an open-source project, allowing free use and modification of its software, which is maintained by a community of volunteers. The goal of Doctrine is to provide high-quality and flexible database solutions for PHP developers.