Mastering is the last step of this whole creation process, and it's aim is to achieve a well balanced mix and a high volume for the final song. Instead of working with separated tracks, you just work with the final mix of the song, so that your processements affect the whole song. First of all, Mastering is the most difficult step, and sometimes 2 or more studios separated from the mixing one are requiered to approach this process, and so because of the fact that I couldn't manage to find these resources, I tried to do my best at my home studio to do this step by using a Mixing Assistant called Ozone Izotope 8, which helped me knowing what to do at any point of the process in order to achieve a bright and powerfull mix.