In shari'ah terminology khilaafah is synonymous with 'Imaamah' and 'Imaaratul A'mmah' [The General Authority] 'Sultaanul A'zam' [The Greatest Authority]........We say the Khilaafah of Abu Bakr......meaning his leadership, his government, his administration..........khaleefah is the one who succeeded and in shari'ah terms is synonymous with 'Ameerul Mu'mineen', 'Imaam', and in some cases the text may say 'Raa'in', 'Sultaan', 'Wali' but these latter three terms are not specific and can be used for positions of lesser authority.

However, we should know that when we say 'khilaafah' this does not mean darul Islam, darul Islam is a land controlled by the Muslims where shari'ah is the only law. Many people today think 'khilaafah' means darul Islam. Rather they mix this with certain Quranic phrases that derivve from 'khalafa' 'to succeed' but do not imply the shari' leadership of the Imaam but rather apply the verb to something else........that being the succession of leadership of other nations in terms of dominance, power and influence in the world. So the phrase may come like this 'yastakhlifakum fil ard' 'to make you succeed in the earth' or 'layastakhlifannahum fil ard' 'we will make them succeed in the earth' These phrases are not talking about Imaamah but are rather in the plural form and talk about the UMMAH as a WHOLE and these verses and their context mention TAMKEEN 'power' and also they are a combined phrase which mentions the subject matter 'fil ard' IN THE EARTH, so the subject matter is the control of the DAR [land]......However, apart from this phrase that people confuse when we say 'khilaafah' and khaleefah we are referring not to darul Islam and the leader.......but we are referring to the same thing, th shari'ah leadership.......in other words it is correct to say 'THERE IS NO KHALEEFAH without KHILAAFAH' as there can be no lSUCCESSOR without SUCCESSION having occured. HOWEVER, it is not correct to say 'THERE IS NO KHALEEFAH without DARUL ISLAM' This is because leadership is obligatory regardless of existence of power or not and the subject matter of 'KHILAAFAH' is leadership and governance of the affairs of the ummah (regardless of their circumstances) and not governance of muslims in power.