| 23 |  | Like in a car, to plug the piece A with piece B it needs to maintain a compatibility, for that, every application needs to have a header data of how it works (data asked, data returned, options, etc) and a version number.  | 
          
            |  | 23 | Like in a car, to plug the piece A with piece B it needs to maintain a compatibility, for that, every application needs to have a header data of how it works (data asked, data returned, options, etc) and a version number. Think about it like individual programs that understand if they are compatible with eachother. |