What are the phases of gymnastics?

What do you mean by phases? If you mean levels then there are 10 levels and then elite. It is really hard to make it to elite unless you start at a really young age. The higher the level the harder the skills are. Like in level 5 floor routine you do round off double back handsprings. And in the level 6 floor rutine you a round off back handspring back tuck. Then in level 7 you make up your own rutines and they have certin requirements that you have to do.