The ADD button is used to send audio video files directly to MB STUDIO PRO. This way you can quickly overwrite one file with another file. Let's take a practical example: at 4PM MB STUDIO PRO broadcasts the time sequence of the news program which includes the news.mp3 file. We could record at home a new file news.mp3 and with the ADD + SEND button we load it on MB STUDIO PRO and the new file will automatically replace the old one. If, on the other hand, it is a new file that is not yet present, MB STUDIO PRO deposits it in the MBRemoteUpload \ Username folder and remains there waiting for you to program it in some playlist or time sequence.