Differences between Sap Data Quality Management Software and Data Services?

Hi Everyone,

I am new to Data Services and Data Quality.I would like to know the differences between Data Quality Management Software & SAP Data Services. Basically, Data Services has already data quality in it,then what is the need of Data Quality Management Software, In which scenario we have to use Data Quality Management? Which one is cost effective?  Can you please answer my questions.

Thanks for the reply in advance.

Thanks & Regards,

Mahesh Kumar.