When working with Genero form files, you will either edit a .per file in any text editor including the Genero Studio Code Editor, or you may elect to edit a .4fd file in Genero Studio using the Form Designer. The Form Designer and its GUI IDE gives you a near WYSIWYG experience, whilst using the Code Editor, you have to use a little imagination to think about what the finished screen will look like.
From a functionality point of view, there is no difference between using a .per and a .4fd, the benefit is the time spent with the developer creating a form. A GUI IDE in theory allowing you to be closer to getting it right first time rather than a cycle of a few refinements as might happen in a text editor.
Underneath a .4fd file, if you open it in a text editor you will see that it is XML. XML files can suffer at merge time with your version control system / source code repository. If two or more developers have worked on the same file independently, any merge conflict may have to be resolved by editing the XML manually, rather than in the GUI IDE
Read more at
https://4js.com/ask-reuben/ig-165/
