Cultural Diffusion: The spread or transfer of cultural elements (such as languages, customs, religions) from one society or group to another.
Missionary Activities: Efforts made by individuals or groups belonging to a particular religion (in this case Islam) to propagate their faith among others who may not be familiar with it.
Hajj: The annual pilgrimage to Mecca in Saudi Arabia which is one of the Five Pillars of Islam. It facilitated the exchange of ideas and cultural influences among Muslims from different regions during their journey to Mecca.