I have an entity and I've realised that there is a group of properties that work together. So, I moved them to a value object (together with their behavior) and now I have a reference from my entity to this value object.
I've read "Domain Driven Design Quickly" (PDF) and I came across the following statement when explaining Value objects:
If Customer is an entity object, then one instance of this object, representing a specific bank client, cannot be reused for account operations corresponding to other clients. The outcome is that such an instance has to be created for every client. This can result in system performance degradation when dealing with thousands of instances.
But I'm still not clear exactly what this means. Is my new object a value object or should it be an entity? I am having trouble reasoning whether it should in fact be an entity. In other words, what questions should I ask in my domain to assure me that it should be a value object?