Which database does Sitecore primarily use for content storage?

Sitecore primarily utilizes Microsoft SQL Server for content storage. This choice is integral to Sitecore's architecture as it allows for robust data management, query capabilities, and reliability that are essential for a content management system (CMS). SQL Server supports transactions, indexing, and complex querying, which are crucial for managing large volumes of content effectively.

Additionally, Sitecore's extensibility and integration features are well-suited to work with SQL Server, making it the default choice for storing not only content but also usage data, configuration settings, and user data. This alignment with Microsoft technologies enhances compatibility and performance, further solidifying SQL Server's role in Sitecore’s ecosystem.

The other database options may not provide the necessary support and features suited for a comprehensive CMS like Sitecore, limiting their applicability in this context. For example, while Oracle and MySQL are robust databases, and MongoDB offers advantages for certain types of applications, they do not align with Sitecore’s core design philosophy and support requirements.