diff between properties without or with @property ?

[D-ratiseur]

Hello, what's the difference between a property declared  without 
a @property block and another one with? It seems that both forms 
are possible:

---
void Prop1(int AValue);
int Prop1();
or

@property
{
    void Prop1(int AValue);
    int Prop1();
}
---

Does it has something to do with the RTTI/serialization such as 
the "published" keyword in Pascal ? I cant find any clue in the 
manual.