Can someone please explain the difference? Are they the same product, and if not, what are they used for?
Crystal Reports is a design tool — you use it to create and maintain reports. This is similar to Desktop Intelligence and Microsoft Access. It also has an SDK (COM, .Net, Java) for programmatic access.
BusinessObjects Enterprise is a platform for deploying reports:
Business objects is an enterprise that specializes in business analytics and provides tools that mainly help in the analysis, reporting of corporate data.
Crystal Reports primarily covers the design and creation of various types of reports from different data sources. It was acquired by business objects.
In addition to the response received, Crystal Reports Server is a limited version of Business Objects Enterprise.