What is the difference between BI and BW?

What is the difference between BI and BW? Is it required to have programming knowledge for learning BI/BW?

BW refers to SAP BW which is SAP Data Warehouse. Up to version 3.5, BW is being called by the name SAP BW. From version 7.0 onwards, the name has been changed to SAP BI. BI refers not just Data Warehouse, but a complete set of products provided by SAP to build a Business Intelligence system.