What does the term 'Centre of Excellence' mean when it comes to hospitals?

One of the questions patients and their families can ask to verify a COE is about their complication rates, which includes the number of patients who have to return to the operating theatre, be readmitted and/or die from complications. — AFP

There has been a global move by healthcare facilities in meeting targets to achieve excellence in their service delivery.

Many healthcare facilities that are globally recognised for their expertise, skills and research have established Centre(s) of Excellence (COE).