These two benefits Data Cloud provides a company in relation to managing customer data. Unified Identity Resolution allows a company to link data from different sources and create a single view of each customer.
Data Harmonization allows a company to standardize and enrich data from different sources and improve data quality and usability. References:
https://help.salesforce.com/s/articleView?id=sf.c360_a_data_cloud_identity_resolution.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.c360_a_data_cloud_data_harmonization.htm&type=5