Whereas a program may implement classes, which typically end in objects managing or executing behaviors, a business object usually does nothing itself but holds a set of instance variables or properties, also known as attributes, and associations with other business objects, weaving a map of objects representing the business relationships.
A domain model where business objects do not have behaviour is called an anemic domain model.
Business objects separate state from behavior because they are communicated across the tiers in a multi-tiered system, while the real work of the application is done in the business tier and does not move across the tiers.
For example, a "Principal" would be a business object where its attributes can be "Name", "Second name", "Age", "Area", "Country" and it could hold an 1-n association with its employees (a collection of Employee instances).
Another example would be a concept like "Process" having "Identifier", "Name", "Start date", "End date" and "Kind" attributes and holding an association with the "Employee" (the responsible) that started it.
- Rockford Lhotka, Visual Basic 6.0 Business Objects, ISBN 1-86100-107-X
- Rockford Lhotka, Expert C# Business Objects, ISBN 1-59059-344-8
- Rockford Lhotka, Expert One-on-One Visual Basic .NET Business Objects, ISBN 1-59059-145-3
- Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides, Design Patterns, ISBN 0-201-63361-2