Source: Business Insider
No religion is unified. How Catholicism, for example, is practiced in rural Italy differs from the way this is done, say, in New York city. Language, culture, tradition, the political and social contexts, and even food is different in these two places.
Such geographic differences are certainly important in Islam. But also important are the numerous legal schools and their interpretations. Since Islam is a religion predicated on law (sharia), variations in the interpretation of that law have contributed to regional differences.