INTERFACE

An connections contains strategies which are all summary and none of the techniques will have system. only technique model will be published in the user interface. So and user interface can be defined as a requirements of technique protocol. Since we make only summary techniques in the user interface there is possibility for providing different implementations (body) for those summary techniques depending on the requirement objects

INTERFACE:
    An user interface contains only summary techniques are all in completed techniques. So it is not possible to make an object to an user interface. In this case we can make separate sessions where we can applied all the techniques of the connections. These sessions are called execution sessions. Since execution sessions will have all the techniques with system it is possible to make things to the execution sessions. The flexibility lies the fact that every implantation category can have its own execution of the summary technique of the user interface. See Figure

       By standard the user interface techniques are community and summary. Hence user interface contains only the summary technique and by standard user interface varying are community fixed final.
Let us see how the user interface concept is advantages in application development. A developer is requested to make a coffee program to get connected to a information source and recover the information from the information source process the information and display the result in the form of some reports. For this purpose the developer has published a category to get connected to oracle details source some thing like this:

//class to link and detach from oracle
class Myclass
{
     gap connect()
     {
           //write value to get connected to oracle information source
      }
   gap disconnect()
     {
           //disconnect from oracle database
       }
}
      This category has a restriction. It can link only to oracle information source. If a client (user) using any other information source (for example sybase database) uses this value get linked to his information source this value will not work. So the developer is requested to design his value in such a way that it used to get connected to any information source on the globe. How is it possible?
       one way is to make several sessions each to get connected to a particular information source. Thus considering all the information source available on the globe the developer has make a lot of sessions. This takes a lot of persistence. Even though the developer usually spends lots of your energy and energy and creates all the sessions by enough time the application is released into the market all the variations of the information source will change and the developer is supposed to reword the sessions again ti suit the latest version of data source. This is very complicated.