The document discusses the concept of polyglot persistence and multi-model databases, highlighting the shift from single-model databases to more flexible systems that can store multiple data formats like key-value pairs, documents, and graphs. It emphasizes the benefits of this approach, such as tailored queries, optimized data storage, and a focus on business logic while managing redundancy and synchronization challenges. Key features of multi-model databases, specifically ArangoDB, include AQL for complex queries, ACID transactions, and the ability to extend functionality with Foxx microservices.