Please find the below example.
Here you are looking at the Sum(Sales) by region. (Aggregated).
In the below screenshot you are looking at the [Sales] view by Region. (non-aggregated)
This non-aggregated view is giving you the each and every sales transaction against the region where as above aggregated one is giving you Sum of all the transaction by region. Non-aggregation worked at row level by region and Aggregated one worked at the region level and providing you single value.
I hope this helps.
Thanks and Regards,