There are a lot of differences but unique similarities ,I will address the later in my answer : 1.One language : all of these countries ,share the same language which is Arabic. 2.One religion : Islam is the dominant religion . 3.One history : All of Levant countries, gulf countries and north Africa countries were occupied at one point of time by western powers.

First thing I can think of it is food. Each region has it's own common food. Once the Tunisian president Habib Bourguiba have been asked that today which countries can be categories among Maghribi countries, and his answer was whenever you see Couscous know that country is Maghribi country. Adding to the food list Baziin, and Zammitta. These plates are originally Amizghe food so they only exist in Maghrib region. Also Arabs in Maghrib region have their own unique dishes which can not be found on other Arabic countries. Another differences is the traditional cloth, music and wedding dances. Religions and races diversity can be add. For example, in Maghrib region all Muslims are Sunni. Beside Arabs here we have Amizghe, and Tabu.

They are very different. A saudi or Egyptian can't understand when a Moroccan or Algerian speaks. The genetics are very different as well.