these object or models which hardly have any behavior they are more of set of setter and getter, although you might think it looks like a real domain model because it might have a name after a noun in the domain space and also might be connected with a rich relationship and structure that true domain models have. The fundamental horror of this anti-pattern is that it’s so contrary to the basic idea of object-oriented design; which is to combine data and process together.
original post about anemic domain model