In a database management system, physical data models describe the details of how data is actually stored on computer storage devices such as disks and SSDs. Is this statement correct?

Introduction / Context:
Database systems are often described using multiple levels of abstraction, including the external, conceptual, and internal or physical levels. While higher level models focus on how users see data, physical data models are concerned with how the data is actually laid out on storage media. This question checks whether you can correctly associate physical data models with low level storage details such as record formats, file structures, and access paths.

Given Data / Assumptions:

• The statement says that physical data models describe details of how data is stored in computers.
• We interpret storage to mean disks, SSDs, and other persistent media.
• We assume standard three level architecture terminology from DBMS theory.
• We assume that physical data models include file organizations, indexes, and access methods.

Concept / Approach:
At the physical level, the database designer specifies how tables, records, and indexes are organized in files and on storage blocks. Physical data models capture details such as the choice between heap files and indexed files, the structure of B tree or hash indexes, clustering strategies, and record storage formats. These details are crucial for performance but are typically hidden from end users. By contrast, conceptual and external models focus on entities, attributes, and views, not on how bits are placed on disk.

Step-by-Step Solution:
Step 1: Recall the three level schema architecture: external, conceptual, and internal or physical.Step 2: The physical or internal level deals with files, indexes, and storage structures.Step 3: The statement claims that physical data models describe details of data storage.Step 4: Compare this description with your knowledge of physical design topics in DBMS courses.Step 5: Conclude that the statement matches the standard role of physical data models, so it is correct.

Verification / Alternative check:
In practice, when a database is tuned for performance, administrators adjust storage parameters, create or drop indexes, and choose file organization strategies. These actions belong to the physical level and are guided by the physical data model. For example, deciding whether to cluster records by a certain key affects how data is stored on disk. This confirms that physical data models indeed describe storage details rather than user oriented structures.

Why Other Options Are Wrong:
Option B (Incorrect) is wrong because the statement accurately reflects the role of physical data models. Option C (Only true for logical models) is incorrect since logical or conceptual models describe meaning and relationships, not storage details. Option D (Only true for external schemas) is also wrong, because external schemas define user views and do not specify low level storage mechanisms.

Common Pitfalls:
A frequent confusion is between logical and physical design. Students may think that creating tables in SQL already includes all physical decisions, when in fact many storage details are decided later. Another pitfall is to assume that end users need to understand physical data models, whereas the whole point of data independence is to shield users and even many application developers from these low level details. Remembering that physical models are about storage and performance helps keep the levels clear.

Final Answer:
The statement is Correct, so the correct option is "Correct".