Question: What is O/R mapping?

Solution: O/R Mapping, or Object Relational Mapping, is the general term for the concept of creating mappings between tables and their fields, and Object Oriented (OO) classes and their fields to be able to represent a table row in an OO program via a class. O/R Mapping is not new; in the Java world it is a common technique to work with data in a database. For developers using Microsoft platforms and .NET in particular, O/R Mapping is rather new and often mis-understood, since most Microsoft oriented developers think in tiers.