WordPress is a content management system that powers substantial parts of the internet. Like many other applications, WordPress uses a relational database to store articles, comments, users, and many other data. It is fair to say that relational databases are the de facto standard for storing and querying structured data, and many applications are built on top of a relational database system such as MySQL. Typically, relational databases focus on data consistency and guarantee ACID (atomicity, consistency, isolation, and durability) database transactions. A typical task is storing and querying structured data, such as the accounts and transactions in an accounting application. If you want to use a relational database on AWS, you have two options: