Step 1: Understanding the role of schemas in a database.
A schema is the overall design or blueprint of a database.
Database systems generally deal with:
• Physical Schema
• Logical (Conceptual) Schema
• External Schema
These schemas describe how data is stored, organized, and presented to users.
Step 2: Determining which language defines schemas.
The language responsible for creating and defining database structures is Data Definition Language (DDL).
Examples of DDL commands include:
\[
\texttt{CREATE, ALTER, DROP, TRUNCATE}
\]
These commands establish the structure of the database and therefore define schemas.
Step 3: Understanding access authorization.
Access authorization refers to permissions and privileges granted to users.
Database systems use definition-related commands and authorization mechanisms to establish who can access various database objects.
Thus, schema definition and authorization management are associated with DDL-related database administration functions.
Step 4: Eliminating incorrect options.
• DML works with data, not schema definitions.
• LDL is not a standard database language.
• Data-Driven Language is not a recognized schema-definition language.
Therefore, the language used to define logical, external, and physical schemas along with access authorizations is:
\[
{\text{Data Definition Language (DDL)}}
\]