Hi @TanyaS58 , 

A data type is pega is similar to a data table that will store the structured data. 

When We create a Data Type PRPC automatically Creates Below Components and Rules.

1. It is going to create a Concrete Class Under Data Class.
2. Properties (Which are like columns of table)
3. Physical (Dedicated) table gets created in Rule Base.
4. Data base Table mapping rules gets created.
5. Data Pages (List Type Pages, Page Type and Savable)
6. Report Definition

When you imported data within the data type it was saved in the designated data table records. Hence pega provides the data pages that are basically the layer that connects your database data to your application flow. In pega the data pages can be either of the Type Page or List depending on how they will load the data. Each data page is associated with a source that defines how the data is loaded into these data pages and then presented back to the application flow, where ever they are called.

The report definition acts as a source to your list structured data pages, where via them we run the query to retrieve the data from the data tables which is loaded to the data pages.