In the SAP ABAP Data Dictionary, what is the key difference between a structure and a transparent table?

Introduction / Context:
The SAP ABAP Data Dictionary defines different types of objects that describe business data. Two common objects are structures and transparent tables. Many beginners mix these two because both contain fields and technical information. This question checks if you understand that the main difference lies in physical data storage and the intended use at runtime.

Given Data / Assumptions:

• A transparent table maps one to one to a physical table in the underlying database.
• A structure is a purely logical definition of fields without its own physical storage.
• Both are defined in the ABAP Data Dictionary and can be referenced in ABAP programs.
• The question asks for the key difference, not every minor detail.

Concept / Approach:
A transparent table is used to store persistent business data. Each transparent table created in the ABAP Data Dictionary is also created as a table in the database with the same name and structure. A structure, on the other hand, is used mainly as a blueprint for work areas, internal tables, and interfaces. Structures are not stored as separate physical database objects; they only describe a grouping of fields that ABAP programs can use. The core idea is that tables hold data, while structures describe data layouts without storage.

Step-by-Step Solution:
Step 1: Recall that persistent business data such as sales orders or material masters must be stored in transparent tables. Step 2: Remember that structures are often used in ABAP as work areas or for passing parameters to function modules or methods. Step 3: Review each option and look for the one that contrasts physical storage versus logical definition. Step 4: Option A clearly states that structures do not store data physically, while transparent tables do, which matches the standard ABAP Data Dictionary concept.

Verification / Alternative check:
You can verify by thinking about SQL access. You can write SELECT statements directly against a transparent table name because it exists physically in the database. You cannot write a direct SQL query against a pure structure because it has no database presence. You can, however, declare ABAP variables of type structure and use them in programs. This simple check confirms the explanation in option A.

Why Other Options Are Wrong:
Option B is wrong because buffering relates to table technical settings, not to structures, and transparent tables can be buffered under certain conditions. Option C is incorrect because primary keys are defined for tables, not for structures. Option D is misleading because client dependency is defined at table level; structures do not store data so the concept does not apply in the same way. Option E is wrong because both structures and tables can be transported between SAP systems using the transport system.

Common Pitfalls:
Learners often assume that because structures and tables look similar in the Data Dictionary, they behave the same at runtime. Another common mistake is to believe that any field list defined in the Data Dictionary must be a table. Remember that structures are reusable field groups for program logic, while transparent tables represent database tables for persistent data. Keeping this distinction clear will help when designing data models and ABAP programs.

Final Answer:
A structure does not store data physically and is used only in ABAP programs, whereas a transparent table has a physical database table and stores data persistently