Was post classical European kingdoms mostly similar or mostly different from Islamic caliphates?

Post-classical European kingdoms and Islamic caliphates exhibited both similarities and differences. Both systems were characterized by feudal structures and a strong emphasis on religion in governance, with Christianity in Europe and Islam in the caliphates playing central roles. However, they diverged significantly in their political organization, cultural practices, and approaches to science and philosophy, with Islamic caliphates often fostering a more unified political and cultural identity across vast territories. Additionally, the level of urbanization and trade differed, with many Islamic regions experiencing greater economic integration and cultural exchange during this period.