posted 16 years ago
"unidirectional" refers to an association between two objects that is only one way. So, for example, if a Person object has an Address object, but an Address object doesn't have a Person object, that association would be one way, or unidirectional.
"one to many" is a description of the multiplicity of a relationship between two objects. The term itself is not unique to Hibernate, you'll see it in ER modelling and UML amoungst other models. It describe a relationship where our Person object can have many addresses, but an addres may only have one Person object. If you are going to work with relational databases at all, I'd recommend hunting out some material on this sort of concept. Have a google for "ER modelling" and you'll get lots of articles.