IMAMAT literally means to Lead; IMAM means Leader.
In Islamic terminology Imamat means 'Absolute command of the Muslims in all religious and secular affairs, in succession to the Prophet.'
IMAM means 'The man who, in succession to the Prophet, has the right to the Absolute Command of the Muslims in all religous and secular affairs.'
The word 'man' signifies that a woman can not be Imam.
'Absolute command' excludes those who lead in the prayers: they are also called 'Imam of prayers', but they do not have absolute authority.
'In succession to the Prophet' denotes the difference between a Prophet and an Imam. The Imam enjoys this authority not directly, but as the sucessor of the Prophet.
The world KHILALAT means 'to succeed' and KHALIFA means 'successor'.
In Islamic terminology KHILALAT and KHALIFA signify the same meanings as IMAMAT and IMAM respectively.
WISAYAT means 'the Executorship of the Will', and WASI means the 'executor of the Will.' Their significance in Muslims' writings is the same as that of Khilafat (Caliphate) and Khalif (Caliph).
It will be interesting to note that many previous prophets were also the Caliphs of their predecessor prophets. Thus they were 'Nabi' and 'Khalifa' both; while other prophets (who brought new Sheriats) were not Caliph of any pervious prophet; and there were Caliphs of the prophets who were not prophet themselves.
The question of Imamat and Caliphate has ripped the Muslim community as under and has effected the thinking and philosophy of the different group so tremendously that even the belief in God and the prophets could not escape from this divergence of views.
This sub]ect is the most debated one of Islamic theology. Muslims have written thousands upon thousands of books on Caliphate. The problem before me is not what to write; it is what not to write.
In a small booklet like this one I cannot touch all the topics of this subject; nor can I give all the details of even those topics which will be described herein.
This booklet will be just a brief outline of the differences about the Caliphate.
It will be of help to mention here in the begining that on this question, the Muslims are divided into two sects:
The Sunni, who believe that Abu Bakr was the Caliph of theHoly Prophet of Islam;and
The Shia who believe that Ali Ibin Abu Talib(as) was the Imam and Caliph.
This fundamental difference has led to other differences which will be described in the following chapters.