Magnolia 5.3 reached end of life on June 30, 2017. This branch is no longer supported, see End-of-life policy.
Magnolia has one repository,
magnolia, which in turn contains several workspaces. There is a workspace for storing website content, another for user accounts, third for configuration and so on.
A content repository is a high-level information management system that is a superset of traditional data repositories. It implements content services such as:
A content repository can store text and binary data (images, documents). You don't need to worry about how the data is stored. The repository provides a standardized way to store and retrieve it whether it resides in a traditional database or in a file system.