Value objects (VOs) are also sometimes known as data transfer objects (DTOs). They are used to transfer data between software application subsystems. In addition to passing data within an application, value objects can mirror a server-side object. When this is the case in Flex, you will sometimes see them used with the Flex metadata tag RemoteClass. When the class instance is serialized via Action Message Format (AMF), the RemoteClass metadata tag registers the class with Flex so that Flex preserves type information. This metadata tag can also be used to represent a server-side object in a client application in any server-side language that has an AMF gateway. You use the [RemoteClass(alias=" ")] metadata tag to create an ActionScript object that maps directly to the server-side object. You specify the fully qualified class name of the server-side class as the value of the alias.