When we are looged on the miniSAP, we can see the SAP Easy Access screen, this is the starting point to all the SAP software, and in our case to all the development tools, that we need to develop an ABAP program.
You can be worried about the moment where we can begin to write code here, but first of that we must deal with some configuration tasks, we must to create our Development Request.
With SAP you must follow some best practices to do all, then before you can open a text editor and begin to write your first application, you must to create some things, for example a development request, on a world real development may be you cannot be worried for this task, becouse the transport layer and development request that you must to use is already created by other person, maybe one NW Basis Consultant, your ABAP leader or other more ranged consultant in the proyect, in real proyects you are not alone, there are many people working around you, but here in miniSAP you are the one user and developer. This situation is good becouse you can know some tasks that are happening aroung you, and it's good to know.
Ok, let's start... SAP have usually three different systems, the first and more important for us is the development system, here and only here we create our ABAP programs, and we can test and debug our program here until we can say that the program is completed, when the program is completed this program must be transported to other system, usually called QAS, in this system some SAP users test your development and if they see all ok, your program is finally transported to the final system: the production one.
Then the transport layer is the layer, path or way, that will transport your development between the SAP systems, and this layer must to exists before you begin your development. By default this MiniSAP have only the transport layer called SAP, this layer must be used only by objects created by SAP. MiniSAP don't have three systems, just have one for development, but it's good to know what happen on a real SAP enviroment.