Aggregate Data Type is use to create higher-level structures, and for a more effective data use.  A proper used of sturctured data helps to make programs less complicated, easier to understand and maintain.
 

Benefits of Structured Data:

• Avoid one-off errors - In languages that have zero-based indices, it is common for programmers to try to access memory outside the bounds of the aggregate data type. Know your limits; use sizeof()!
• Use structured data to make the relationships between data clear.
• Use structured data to make operations of blocks of data simpler.
• Use structured data to make parameter passing clearer, easier and simpler. 

An abstract data type is a collection of data and operation that work on that data.

Benefits of Using Abstract Data Type:

• Support informastion hiding
• Minimize the effect of changes in program. 
• Improve ability to enhance code
• Program becomes more self-documenting
• Allows for object-oriented concepts
• It defines operations dealing with real-world entities

Example Set #1:  A large C++ program showing good and bad examples of all four tips.
Example Set #2:  C++ example - good and bad use of structured data
Example Set #3:  Java example - good and bad use of structured data
Example Set #4: C example - bad use of structured data