what is business object
what is BUSINESS OBJECTS IN SAP-BW?
Business Object is a reporting tool which is similar to SAP BI. SAP BI is very strong at reporting, modelling and extraction. where as Business Objects is good at look and feel as well as analytics. So, recently SAP and BO are integrated so that there will be more advantage for the end user.
you can have a look at following blogs for better understanding: