Define Query Interface,Adref,Release

QueryInterface is used for determining if a known component supports a specific interface.It is a mechanism in COM (microsofts Component Object Model).It uses the current interface pointer ( IUnknown), by passing an interface ID. If the object supports an interface which matches the ID, it gives back a pointer which can be cast into a pointer to the correct type of interface.

adref is used to increment the reference count.

release is used to delete an object when reference count reaches zero.