Explanation:

- Database Instance: Represents the actual data stored in a database at a particular moment in time. It is the state of the database’s content.

- Database Snapshot: A read-only static view of a database, often used for backup or reporting purposes. It does not represent the design or structure.

- Database Schema: The logical design of a database, including its tables, views, relationships, indexes, and other structures. It outlines how data is organized and how they relate to one another.

- All of the above: This option is incorrect because each term has a distinct meaning and cannot all be used to define the logical design of a database.

Correct Answer: Database Schema

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