Discuss the categories in which data is divided before structuring it into data warehouse?

Discuss the categories in which data is divided before structuring it into data warehouse?
Answer: 
Populating is the process of getting the source data from operational and external systems into the data warehouse and data marts. The data is captured from the operational and external systems, transformed into a usable format for the data warehouse, and finally loaded into the data warehouse or the data mart.

Capture
-    Capture is the process of collecting the source data from the operational systems and other external sources.
-    Source data extraction provides a static snapshot of source data as of a specific point in time. It is sufficient to support a temporal data model that does not have a requirement for a continuous history. Source data extraction can produce extract files, tables, or image copies.

Transform
-    The transform process converts the captured source data into a format and structure suitable for loading into the data warehouse. The mapping characteristics used to transform the source data are captured and stored as metadata.
-    Transformation of data can occur at the record level or at the attribute level. The basic techniques include structural transformation, content transformation, and functional transformation.

Apply
-    The apply process uses the files or tables created in the transform process and applies them to the relevant data warehouse or data mart.
-    There are four basic techniques for applying data: load, append, constructive merge, and destructive merge.