Why does health care data need to be aggregated? In the data aggregation process, what is the impact of using information that is assigned a code as opposed to free text data?

Data Aggregation

What is the difference between structured and unstructured data? Compare the impact of using structured versus unstructured data.
Why does health care data need to be aggregated? In the data aggregation process, what is the impact of using information that is assigned a code as opposed to free text data?