Datasource Vs PSA - What's the difference (SAP BW 7.5 On HANA)

SAP BW PSA : 

PSA (Table) is created once the Datasource is activated in the BW system. 

Hers is some major differences :

DataSource	PSA
DataSource is an BW Object to fetch data from source system into BW system	PSA is an table that is created based on the DataSources Transfer Structure.
DataSource do not store data	PSA Store data for a specific datasource
SAP Delivers standard DataSource	There is no standard PSA, It is created once the SAP Delivered data source is activated
Datasource has many properties like whether it supports delta/Full load from source system	PSA is primarily used only for storing data
We can add new fields to a DataSource. This will create a new PSA Version.	We can delete data from a PSA Table, This will in turn affect the DataSource.
DataSource will be created in BW system once its replicated from the source system.	PSA Table will be created only when a datasource is activated