The data directory is the place where MySQL 8 stores all the information that is managed by itself. Each sub-directory of the data directory represents a database directory and its related data. All the MySQL installations have the following standard databases:
- The sys directory: This represents the sys schema, which contains the objects useful for the Performance Schema information interpretation.
- The performance schema directory: This directory is used to observe the internal execution of the MySQL server at run-time.
- The mysql directory: This directory is related to the MySQL system database, which contains the data dictionary table and the system tables. It contains the information that is required by the MySQL server once it is running.
