Various opportunities and the career development pathway is very well laid out
Promotion opportunities are good, with moving up contingent on being able to demonstrate the neccessary skills to have the solo responsibility of the next level. You and your manager discuss moving up, with either an in-line in the same role or a move to a different open role, and after you think you are ready you then start the official process which assesses you for readiness to move. After that is completed you will either be approved for a promotion or reccommended for further development in certain areas.
There are very clear pathways to progress in your career, some formal and some more very unformal ways. It is a company where your hard work does pay off.