An action is the first step in building an Android application. For instance, the likes of opening a contact and dialling someone. Everything is finished by communicating with a window and that very window is given by an action. Whether you make a taxi app or any other, every Android application has more than one movement. At whatever point, there is another window begins, past movement is pushed to the back stack and it is halted until the new action is finished. When the back key of your gadget is squeezed, new movement is jumped out of stack, aka closed. Did you find this useful?