This type of terming or naming being called "Islamic terms"...
This type of terming or naming being called "Islamic terms" and "Shar'i terms" meaning terms or names that were chosen legally or by the legislator. There is also another group of words called "Motashareh terms" which were chosen by the Muslims themselves or by Islamic scholars. We said that the word Caliph with its present meaning (religious leader and leader of the Muslim world) is not a Shar'i or canonical term.
This means that during the Prophets' lifetime this word did not possess this meaning, the Muslims themselves or the followers of the Caliphate school have given it this meaning. According to this, whenever we see the word caliph in the Quran or Tradition it has its literal meaning, the very meaning the Arabs understood it to have, its completely literal meaning.
If a scholar were to appoint someone to take his place, and leave all of his duties for him to perform, such a person would become "Khalifatul'alim" or "Caliph of the scholar". Or if a merchant were to appoint someone to take his place in his business making him his successor, he thus becomes "Khalifato-at-tajir" or "Caliph of the Merchant". Because it is used in conjunction with God in the Quran it means "Khalifaullah" or "Caliph of Allah".
He is the man who has obtained the power of authority to do Gods work in the world. In the Prophets tradition, caliph means that person who performs the special duty of the Prophet, or first hand propagation, and who in reality was charged with the continuation of the Prophet's work. Since the never ending duty of the Prophet is the propagation of Islamic religious law, his caliph is also the propagator of religious law.
As such, neither in the Quran, nor in Tradition does the word Caliph carry the meaning of Islamic leader or governor. On the contrary, in the tradition of the Prophet, whenever we see this word, for example where it is said "Khalifati feekom" with regard to Ali (a.s), it does not mean governor or leader but means that; after me the propagation of Islam is his responsibility. The explanation and interpretation of the Quran is his responsibility.
104 After clarifying this matter we will begin a study of the reasoning of these two schools. The description and reason behind the Caliphate schools opinions will be extracted from the books we mentioned earlier, named "Al-Ahkamu's-sultaniyyah" by Qazi Mawardi (born in the year 450 A.H.) and Qazi Abu Ya'la (born in the year 458 A.H) both high ranking judges during their time.