In ABAP (Advanced Business Application Programming), a structure is a data type that allows you to group related data elements under a single name. It is defined in the ABAP Data Dictionary and serves as a way to organize and encapsulate fields, making it easier to manage and reuse data structures in programs. Here is how a structure is defined in the ABAP Data Dictionary:

Steps to Define a Structure in ABAP Data Dictionary:

1. Transaction Code:

   • To define a structure, you typically use the ABAP Dictionary transaction code SE11 (Data Dictionary).

2. Choose Data Type:

   • In the initial screen, choose the data type for which you want to create a structure. Common data types include tables, views, and data elements.

3. Enter Structure Name:

   • Enter a name for your structure in the "Data type" field. This name uniquely identifies your structure in the ABAP Data Dictionary.

4. Create/Change/Display:

   • Click on the "Create" button to create a new structure. If you want to modify an existing structure, select it and click "Change" or "Display."

5. Fields Tab:

   • In the "Fields" tab, you can add the individual data elements that make up your structure. Each field has attributes such as name, data type, length, and decimal places.

6. Field Attributes:

   • Define the attributes for each field within the structure, including the field name, data type (e.g., CHAR, NUMC, INT), length, and other properties.

7. Save and Activate:

   • Once you have defined the fields, save your structure. If it's a new structure, you may need to activate it to make it available for use in ABAP programs.